System Framework for a Multi-Band, Multi-Mode Software Defined Radio
2014-06-01
being developed for next- generation telemetry applications. The system framework consists of a multi-band front-end (MBFE), a multi-mode digital... telemetry waveforms. Finally, the C2 consists of the software and hardware components for system configuration, control and status. The MBFE is...a-chip (SoC) technology. Design methodologies, hardware architectures, and system tradeoffs are highlighted to meet next-generation telemetry
A robo-pigeon based on an innovative multi-mode telestimulation system.
Yang, Junqing; Huai, Ruituo; Wang, Hui; Lv, Changzhi; Su, Xuecheng
2015-01-01
In this paper, we describe a new multi-mode telestimulation system for brain-microstimulation for the navigation of a robo-pigeon, a new type of bio-robot based on Brain-Computer Interface (BCI) techniques. The multi-mode telestimulation system overcomes neuron adaptation that was a key shortcoming of the previous single-mode stimulation by the use of non-steady TTL biphasic pulses accomplished by randomly alternating pulse modes. To improve efficiency, a new behavior model ("virtual fear") is proposed and applied to the robo-pigeon. Unlike the previous "virtual reward" model, the "virtual fear" behavior model does not require special training. The performance and effectiveness of the system to alleviate the adaptation of neurons was verified by a robo-pigeon navigation test, simultaneously confirming the practicality of the "virtual fear" behavioral model.
Multi-Mode Analysis of Dual Ridged Waveguide Systems for Material Characterization
2015-09-17
Ross-Weir xi MULTI-MODE ANALYSIS OF DUAL RIDGED WAVEGUIDE SYSTEMS FOR MATERIAL CHARACTERIZATION I. Introduction 1.1 Introduction Electromagnetic material...machined or altered in some way in order to fit into the electromagnetic testing device (e.g., waveguide). Destructive techniques often have the...accurately model new designs such as antennas and absorbing coatings. While many numerous techniques exist in the microwave spectrum , their
A multi-mode manipulator display system for controlling remote robotic systems
NASA Technical Reports Server (NTRS)
Massimino, Michael J.; Meschler, Michael F.; Rodriguez, Alberto A.
1994-01-01
The objective and contribution of the research presented in this paper is to provide a Multi-Mode Manipulator Display System (MMDS) to assist a human operator with the control of remote manipulator systems. Such systems include space based manipulators such as the space shuttle remote manipulator system (SRMS) and future ground controlled teleoperated and telescience space systems. The MMDS contains a number of display modes and submodes which display position control cues position data in graphical formats, based primarily on manipulator position and joint angle data. Therefore the MMDS is not dependent on visual information for input and can assist the operator especially when visual feedback is inadequate. This paper provides descriptions of the new modes and experiment results to date.
A multi-mode sensing system for corrosion detection using piezoelectric wafer active sensors
NASA Astrophysics Data System (ADS)
Yu, Lingyu; Giurgiutiu, Victor; Pollock, Patrick
2008-03-01
As an emerging technology for in-situ damage detection and nondestructive evaluation, structural health monitoring with active sensors (active SHM) plays as a promising candidate for the pipeline inspection and diagnosis. Piezoelectric wafer active sensor (PWAS), as an active sensing device, can be permanently attached to the structure to interrogate it at will and can operate in propagating wave mode or electromechanical impedance mode. Its small size and low cost (about $10 each) make itself a potential and unique technology for in-situ SHM application. The objective of the research in this paper is to develop a permanently installed in-situ "multi-mode" sensing system for the corrosion monitoring and prediction of critical pipeline systems. Such a system is used during in-service period, recording and monitoring the changes of the pipelines over time, such as corrosion, wall thickness, etc. Having the real-time data available, maintenance strategies based on these data can then be developed to ensure a safe and less expensive operation of the pipeline systems. After a detailed review of PWAS SHM methods, including ultrasonic, impedance, and thickness measurement, we introduce the concept of PWAS-based multi-mode sensing approach for corrosion detection in pipelines. Particularly, we investigate the potential for using PWAS waves for in thickness mode experimentally. Finally, experiments are conducted to verify the corrosion detection ability of the PWAS network in both metallic plate and pipe in a laboratory setting. Results show successful corrosion localization in both tests.
Integration of geospatial multi-mode transportation Systems in Kuala Lumpur
NASA Astrophysics Data System (ADS)
Ismail, M. A.; Said, M. N.
2014-06-01
Public transportation serves people with mobility and accessibility to workplaces, health facilities, community resources, and recreational areas across the country. Development in the application of Geographical Information Systems (GIS) to transportation problems represents one of the most important areas of GIS-technology today. To show the importance of GIS network analysis, this paper highlights the determination of the optimal path between two or more destinations based on multi-mode concepts. The abstract connector is introduced in this research as an approach to integrate urban public transportation in Kuala Lumpur, Malaysia including facilities such as Light Rapid Transit (LRT), Keretapi Tanah Melayu (KTM) Komuter, Express Rail Link (ERL), KL Monorail, road driving as well as pedestrian modes into a single intelligent data model. To assist such analysis, ArcGIS's Network Analyst functions are used whereby the final output includes the total distance, total travelled time, directional maps produced to find the quickest, shortest paths, and closest facilities based on either time or distance impedance for multi-mode route analysis.
Development of the multi-mode external lighting system for aircraft (M2ESA)
NASA Astrophysics Data System (ADS)
Martin, John J.
2005-08-01
This paper documents the development of the Multi-Mode External Lighting System for Aircraft (M2ESA), a solid-state near-IR and visible light emitting diode-based programmable system designed to replace existing incandescent navigation lights on the exterior of military aircraft, and tailored for use with night vision goggles. Integrated systems of optics, electronics and mechanical structures were designed that were compatible with legacy aircraft systems, and which thus conformed to rigid configuration requirements and severe volume constraints. The genesis of the concept, evolution and general architecture of the system, top-level performance and environmental requirements, integration on the designated aircraft platform (the F-15), and general results of flight demonstration assessments are described.
Design of a Multi-mode Flight Deck Decision Support System for Airborne Conflict Management
NASA Technical Reports Server (NTRS)
Barhydt, Richard; Krishnamurthy, Karthik
2004-01-01
NASA Langley has developed a multi-mode decision support system for pilots operating in a Distributed Air-Ground Traffic Management (DAG-TM) environment. An Autonomous Operations Planner (AOP) assists pilots in performing separation assurance functions, including conflict detection, prevention, and resolution. Ongoing AOP design has been based on a comprehensive human factors analysis and evaluation results from previous human-in-the-loop experiments with airline pilot test subjects. AOP considers complex flight mode interactions and provides flight guidance to pilots consistent with the current aircraft control state. Pilots communicate goals to AOP by setting system preferences and actively probing potential trajectories for conflicts. To minimize training requirements and improve operational use, AOP design leverages existing alerting philosophies, displays, and crew interfaces common on commercial aircraft. Future work will consider trajectory prediction uncertainties, integration with the TCAS collision avoidance system, and will incorporate enhancements based on an upcoming air-ground coordination experiment.
Method and apparatus for controlling a powertrain system including a multi-mode transmission
Hessell, Steven M.; Morris, Robert L.; McGrogan, Sean W.; Heap, Anthony H.; Mendoza, Gil J.
2015-09-08
A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desired input speed and the power limited torque commands for the torque machines.
Adhesive performance of a multi-mode adhesive system: 1-year in vitro study.
Marchesi, Giulio; Frassetto, Andrea; Mazzoni, Annalisa; Apolonio, Fabianni; Diolosà, Marina; Cadenaro, Milena; Di Lenarda, Roberto; Pashley, David H; Tay, Franklin; Breschi, Lorenzo
2014-05-01
The aim of this study was to investigate the adhesive stability over time of a multi-mode one-step adhesive applied using different bonding techniques on human coronal dentine. The hypotheses tested were that microtensile bond strength (μTBS), interfacial nanoleakage expression and matrix metalloproteinases (MMPs) activation are not affected by the adhesive application mode (following the use of self-etch technique or with the etch-and-rinse technique on dry or wet dentine) or by ageing for 24h, 6 months and 1year in artificial saliva. Human molars were cut to expose middle/deep dentine and assigned to one of the following bonding systems (N=15): (1) Scotchbond Universal (3M ESPE) self-etch mode, (2) Scotchbond Universal etch-and-rinse technique on wet dentine, (3) Scotchbond Universal etch-and-rinse technique on dry dentine, and (4) Prime&Bond NT (Dentsply De Trey) etch-and-rinse technique on wet dentine (control). Specimens were processed for μTBS test in accordance with the non-trimming technique and stressed to failure after 24h, 6 months or 1 year. Additional specimens were processed and examined to assay interfacial nanoleakage and MMP expression. At baseline, no differences between groups were found. After 1 year of storage, Scotchbond Universal applied in the self-etch mode and Prime&Bond NT showed higher μTBS compared to the other groups. The lowest nanoleakage expression was found for Scotchbond Universal applied in the self-etch mode, both at baseline and after storage. MMPs activation was found after application of each tested adhesive. The results of this study support the use of the self-etch approach for bonding the tested multi-mode adhesive system to dentine due to improved stability over time. Improved bonding effectiveness of the tested universal adhesive system on dentine may be obtained if the adhesive is applied with the self-etch approach. Copyright © 2014 Elsevier Ltd. All rights reserved.
A Multi-Moded RF Delay Line Distribution System (MDLDS) for the Next Linear Collider
Nantista, Christopher D.
2002-01-17
The Delay Line Distribution System (DLDS) is an alternative to conventional pulse compression, which enhances the peak power of rf sources while matching the long pulse of those sources to the shorter filling time of accelerator structures. We present an implementation of this scheme that combines pairs of parallel delay lines of the system into single lines. The power of several sources is combined into a single waveguide delay line using a multi-mode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted from the delay line using mode-selective extractors, each of which extracts a single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is then fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required by the NLC design while maintaining high efficiency.
A multi-moded rf delay line distribution system for the next linear collider
Tantawi, S.G.; Bowden, G.; Farkas, Z.D.; Irwin, J.; Ko, K.; Kroll, N.; Lavine, T.; Li, Z.; Loewen, R.; Miller, R.; Nantista, C.; Ruth, R.D.; Rifkin, J.; Vlieks, A.E.; Wilson, P.B.; Adolphsen, C.; Wang, J.
1999-07-01
The Delay Line Distribution System (DLDS) (1) is an alternative to conventional pulse compression which enhances the peak power of an rf source while matching the long pulse of that source to the shorter filling time of the accelerator structure. We present a variation on that scheme that combines the parallel delay lines of the system into one single line. The power of several sources is combined into a single waveguide delay line using a multi-mode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted using several mode extractors, each of which extracts only one single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is then fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required by the NLC design, while maintaining high efficiency. {copyright} {ital 1999 American Institute of Physics.}
Energy-efficient multi-mode compressed sensing system for implantable neural recordings.
Suo, Yuanming; Zhang, Jie; Xiong, Tao; Chin, Peter S; Etienne-Cummings, Ralph; Tran, Trac D
2014-10-01
Widely utilized in the field of Neuroscience, implantable neural recording devices could capture neuron activities with an acquisition rate on the order of megabytes per second. In order to efficiently transmit neural signals through wireless channels, these devices require compression methods that reduce power consumption. Although recent Compressed Sensing (CS) approaches have successfully demonstrated their power, their full potential is yet to be explored. Built upon our previous on-chip CS implementation, we propose an energy efficient multi-mode CS framework that focuses on improving the off-chip components, including (i) a two-stage sensing strategy, (ii) a sparsifying dictionary directly using data, (iii) enhanced compression performance from Full Signal CS mode and Spike Restoration mode to Spike CS + Restoration mode and; (iv) extension of our framework to the Tetrode CS recovery using joint sparsity. This new framework achieves energy efficiency, implementation simplicity and system flexibility simultaneously. Extensive experiments are performed on simulation and real datasets. For our Spike CS + Restoration mode, we achieve a compression ratio of 6% with a reconstruction SNDR > 10 dB and a classification accuracy > 95% for synthetic datasets. For real datasets, we get a 10% compression ratio with ∼ 10 dB for Spike CS + Restoration mode.
NASA Astrophysics Data System (ADS)
Sigal, Iliya; Caravaca Aguirre, Antonio M.; Gad, Raanan; Piestun, Rafael; Levi, Ofer
2016-03-01
We demonstrate a single multi-mode fiber-based micro-endoscope for measuring blood flow speeds. We use the transmission-matrix wavefront shaping approach to calibrate the multi-mode fiber and raster-scan a focal spot across the distal fiber facet, imaging the cross-polarized back-reflected light at the proximal facet using a camera. This setup allows assessment of the backscattered photon statistics: by computing the mean speckle contrast values across the proximal fiber facet we show that spatially-resolved flow speed maps can be inferred by selecting an appropriate camera integration time. The proposed system is promising for minimally-invasive studies of neurovascular coupling in deep brain structures.
Development of Radar Control system for Multi-mode Active Phased Array Radar for atmospheric probing
NASA Astrophysics Data System (ADS)
Yasodha, Polisetti; Jayaraman, Achuthan; Thriveni, A.
2016-07-01
Modern multi-mode active phased array radars require highly efficient radar control system for hassle free real time radar operation. The requirement comes due to the distributed architecture of the active phased array radar, where each antenna element in the array is connected to a dedicated Transmit-Receive (TR) module. Controlling the TR modules, which are generally few hundreds in number, and functioning them in synchronisation, is a huge task during real time radar operation and should be handled with utmost care. Indian MST Radar, located at NARL, Gadanki, which is established during early 90's, as an outcome of the middle atmospheric program, is a remote sensing instrument for probing the atmosphere. This radar has a semi-active array, consisting of 1024 antenna elements, with limited beam steering, possible only along the principle planes. To overcome the limitations and difficulties, the radar is being augmented into fully active phased array, to accomplish beam agility and multi-mode operations. Each antenna element is excited with a dedicated 1 kW TR module, located in the field and enables to position the radar beam within 20° conical volume. A multi-channel receiver makes the radar to operate in various modes like Doppler Beam Swinging (DBS), Spaced Antenna (SA), Frequency Domain Interferometry (FDI) etc. Present work describes the real-time radar control (RC) system for the above described active phased array radar. The radar control system consists of a Spartan 6 FPGA based Timing and Control Signal Generator (TCSG), and a computer containing the software for controlling all the subsystems of the radar during real-time radar operation and also for calibrating the radar. The main function of the TCSG is to generate the control and timing waveforms required for various subsystems of the radar. Important components of the RC system software are (i) TR module configuring software which does programming, controlling and health parameter monitoring of the
Effects of boson dispersion in fermion-boson coupled systems
NASA Astrophysics Data System (ADS)
Motome, Yukitoshi; Kotliar, Gabriel
2000-11-01
We study the nonlinear feedback in a fermion-boson system using an extension of dynamical mean-field theory and the quantum Monte Carlo method. In the perturbative regimes (weak-coupling and atomic limits) the effective interaction among fermions increases as the width of the boson dispersion increases. In the strong-coupling regime away from the antiadiabatic limit, the effective interaction decreases as we increase the width of the boson dispersion. This behavior is closely related to complete softening of the boson field. We elucidate the parameters that control this nonperturbative region where fluctuations of the dispersive bosons enhance the delocalization of fermions.
Guo, Haotian; Duan, Fajie; Wu, Guoxiu; Zhang, Jilong
2014-11-15
The blade tip clearance is a parameter of great importance to guarantee the efficiency and safety of the turbine engines. In this article, a laser ranging system designed for blade tip clearance measurement is presented. Multi-mode fiber is utilized for optical transmission to guarantee that enough optical power is received by the sensor probe. The model of the tiny sensor probe is presented. The error brought by the optical path difference of different modes of the fiber is estimated and the length of the fiber is limited to reduce this error. The measurement range in which the optical power received by the probe remains essentially unchanged is analyzed. Calibration experiments and dynamic experiments are conducted. The results of the calibration experiments indicate that the resolution of the system is about 0.02 mm and the range of the system is about 9 mm.
NASA Astrophysics Data System (ADS)
Sun, Xiaoqiang; Yuan, Chaochun; Cai, Yingfeng; Wang, Shaohua; Chen, Long
2017-09-01
This paper presents the hybrid modeling and the model predictive control of an air suspension system with damping multi-mode switching damper. Unlike traditional damper with continuously adjustable damping, in this study, a new damper with four discrete damping modes is applied to vehicle semi-active air suspension. The new damper can achieve different damping modes by just controlling the on-off statuses of two solenoid valves, which makes its damping adjustment more efficient and more reliable. However, since the damping mode switching induces different modes of operation, the air suspension system with the new damper poses challenging hybrid control problem. To model both the continuous/discrete dynamics and the switching between different damping modes, the framework of mixed logical dynamical (MLD) systems is used to establish the system hybrid model. Based on the resulting hybrid dynamical model, the system control problem is recast as a model predictive control (MPC) problem, which allows us to optimize the switching sequences of the damping modes by taking into account the suspension performance requirements. Numerical simulations results demonstrate the efficacy of the proposed control method finally.
Rogue waves for a coupled nonlinear Schrödinger system in a multi-mode fibre
NASA Astrophysics Data System (ADS)
Li, Hui-Min; Tian, Bo; Wang, Deng-Shan; Sun, Wen-Rong; Xie, Xi-Yang; Liu, Lei
2016-10-01
In this paper, we investigate the rogue waves for an integrable coupled nonlinear Schrödinger (CNLS) system with the self-phase modulation, cross-phase modulation and four-wave mixing term, which can describe the propagation of optical waves in a multi-mode fibre. We construct a generalized Darboux transformation (GDT) for the CNLS system and find a gauge transformation which converts the Lax pair into the constant-coefficient differential equations. Solving those equations, we can obtain the vector solutions of the Lax pair. Using the GDT, we derive an iterative formula for the nth-order rogue-wave solutions for the CNLS system. We derive the first- and second-order rogue-wave solutions for the CNLS system and analyse the profiles for the rogue waves with respect to the self-phase modulation term a, cross-phase modulation term c and four-wave mixing term b, respectively. The rogue waves become thinner with the increase in the value for the real part of b and that the effect of a or c on the rogue waves is the same as the one of the real part of b.
Construction of Multi-Mode Affective Learning System: Taking Affective Design as an Example
ERIC Educational Resources Information Center
Lin, Hao-Chiang Koong; Su, Sheng-Hsiung; Chao, Ching-Ju; Hsieh, Cheng-Yen; Tsai, Shang-Chin
2016-01-01
This study aims to design a non-simultaneous distance instruction system with affective computing, which integrates interactive agent technology with the curricular instruction of affective design. The research subjects were 78 students, and prototype assessment and final assessment were adopted to assess the interface and usability of the system.…
Construction of Multi-Mode Affective Learning System: Taking Affective Design as an Example
ERIC Educational Resources Information Center
Lin, Hao-Chiang Koong; Su, Sheng-Hsiung; Chao, Ching-Ju; Hsieh, Cheng-Yen; Tsai, Shang-Chin
2016-01-01
This study aims to design a non-simultaneous distance instruction system with affective computing, which integrates interactive agent technology with the curricular instruction of affective design. The research subjects were 78 students, and prototype assessment and final assessment were adopted to assess the interface and usability of the system.…
Use of anomolous thermal imaging effects for multi-mode systems control during crystal growth
NASA Technical Reports Server (NTRS)
Wargo, Michael J.
1989-01-01
Real time image processing techniques, combined with multitasking computational capabilities are used to establish thermal imaging as a multimode sensor for systems control during crystal growth. Whereas certain regions of the high temperature scene are presently unusable for quantitative determination of temperature, the anomalous information thus obtained is found to serve as a potentially low noise source of other important systems control output. Using this approach, the light emission/reflection characteristics of the crystal, meniscus and melt system are used to infer the crystal diameter and a linear regression algorithm is employed to determine the local diameter trend. This data is utilized as input for closed loop control of crystal shape. No performance penalty in thermal imaging speed is paid for this added functionality. Approach to secondary (diameter) sensor design and systems control structure is discussed. Preliminary experimental results are presented.
Calibration for single multi-mode fiber digital scanning microscopy imaging system
NASA Astrophysics Data System (ADS)
Yin, Zhe; Liu, Guodong; Liu, Bingguo; Gan, Yu; Zhuang, Zhitao; Chen, Fengdong
2015-11-01
Single multimode fiber (MMF) digital scanning imaging system is a development tendency of modern endoscope. We concentrate on the calibration method of the imaging system. Calibration method comprises two processes, forming scanning focused spots and calibrating the couple factors varied with positions. Adaptive parallel coordinate algorithm (APC) is adopted to form the focused spots at the multimode fiber (MMF) output. Compare with other algorithm, APC contains many merits, i.e. rapid speed, small amount calculations and no iterations. The ratio of the optics power captured by MMF to the intensity of the focused spots is called couple factor. We setup the calibration experimental system to form the scanning focused spots and calculate the couple factors for different object positions. The experimental result the couple factor is higher in the center than the edge.
Design of multi-mode compatible image acquisition system for HD area array CCD
NASA Astrophysics Data System (ADS)
Wang, Chen; Sui, Xiubao
2014-11-01
Combining with the current development trend in video surveillance-digitization and high-definition, a multimode-compatible image acquisition system for HD area array CCD is designed. The hardware and software designs of the color video capture system of HD area array CCD KAI-02150 presented by Truesense Imaging company are analyzed, and the structure parameters of the HD area array CCD and the color video gathering principle of the acquisition system are introduced. Then, the CCD control sequence and the timing logic of the whole capture system are realized. The noises of the video signal (KTC noise and 1/f noise) are filtered by using the Correlated Double Sampling (CDS) technique to enhance the signal-to-noise ratio of the system. The compatible designs in both software and hardware for the two other image sensors of the same series: KAI-04050 and KAI-08050 are put forward; the effective pixels of these two HD image sensors are respectively as many as four million and eight million. A Field Programmable Gate Array (FPGA) is adopted as the key controller of the system to perform the modularization design from top to bottom, which realizes the hardware design by software and improves development efficiency. At last, the required time sequence driving is simulated accurately by the use of development platform of Quartus II 12.1 combining with VHDL. The result of the simulation indicates that the driving circuit is characterized by simple framework, low power consumption, and strong anti-interference ability, which meet the demand of miniaturization and high-definition for the current tendency.
TELAER: a multi-mode/multi-antenna interferometric airborne SAR system
NASA Astrophysics Data System (ADS)
Perna, Stefano; Amaral, Tiago; Berardino, Paolo; Esposito, Carmen; Jackson, Giuseppe; Pauciullo, Antonio; Vaz Junior, Eurico; Wimmer, Christian; Lanari, Riccardo
2014-05-01
The present contribution is aimed at showing the capabilities of the TELAER airborne Synthetic Aperture Radar (SAR) system recently upgraded to the interferometric mode [1]. TELAER is an Italian airborne X-Band SAR system, mounted onboard a LearJet 35A aircraft. Originally equipped with a single TX/RX antenna, it now operates in single-pass interferometric mode thanks to a system upgrading [1] funded by the Italian National Research Council (CNR), via the Italian Ministry of Education, Universities and Research (MIUR), in the framework of a cooperation between CNR and the Italian Agency for Agriculture Subsidy Payments (AGEA). In the frame of such cooperation, CNR has entrusted the Institute for Electromagnetic Sensing of the Environment (IREA) for managing all the activities, included the final flight tests, related to the system upgrading. According to such an upgrading, two additional receiving X-band antennas have been installed in order to allow, simultaneously, single-pass Across-Track and Along-Track interferometry [1]. More specifically, the three antennas are now installed in such a way to produce three different across-track baselines and two different along-track baselines. Moreover, in the frame of the same system upgrading, it has been mounted onboard the Learjet an accurate embedded Global Navigation Satellite System and Inertial Measurement Unit equipment. This allows precise measurement of the tracks described by the SAR antennas during the flight, in order to accurately implement Motion Compensation (MOCO) algorithms [2] during the image formation (focusing) step. It is worth remarking that the TELAER system upgraded to the interferometric mode is very flexible, since the user can set different operational modes characterized by different geometric resolutions and range swaths. In particular, it is possible to reach up to 0.5 m of resolution with a range swath of 2km; conversely, it is possible to enlarge the range swath up to 10 km at expenses of
Interface Design Description for the Multi-Mode Magnetic Detection System
2008-11-21
related software development tasks between Polatomic, Inc . (PI) and Applied Signal Technology, Inc . (AST). 1.2 System Overview. The goal of the 3MDS...specification shall be considered a superseding requirement. Copies of specifications, standards, drawings, and publications required by suppliers in...Receiver User’s Guide (Vol. 1 & 2) and are copyrighted by Novatel, Inc . 2. Each log has a header that contains header length, message ID, message
Generating multi-mode entangled coherent W and GHZ states via optical system based fusion mechanism
NASA Astrophysics Data System (ADS)
Zang, Xue-Ping; Yang, Ming; Wu, Wei-Feng; Fan, Hong-Yi
2017-05-01
Fusion technology has been demonstrated to be a good method for generating a large-scale entangled coherent W or GHZ state from two small ones in QED system. It is of importance to study how to fuse small-scale entangled coherent W or GHZ states via optical system. In this paper, we present a scheme for generating larger entangled coherent W or GHZ state in an optical system by virtue of fusion technology. The key fusion mechanism is realized by photon detectors and a Mach-Zehnder interferometer with its two arms immersed in Kerr media, by which an n-mode entangled coherent W state and an m-mode entangled coherent W state can be probabilistically fused into an (n+m-2)-mode entangled coherent W state. This fusion scheme applies to entangled coherent GHZ state too but with a unit probability of success. Feasibility analysis indicates that our fusion scheme may be realized with current experimental technology. Large-scale entangled coherent W and GHZ states may find new applications in quantum communication.
A Research on Development of The Multi-mode Flood Forecasting System Version Management
NASA Astrophysics Data System (ADS)
Shen, J.-C.; Chang, C. H.; Lien, H. C.; Wu, S. J.; Horng, M. J.
2009-04-01
With the global economy and technological development, the degree of urbanization and population density relative to raise. At the same time, a natural buffer space and resources year after year, the situation has been weakened, not only lead to potential environmental disasters, more and more serious, disaster caused by the economy, loss of natural environment at all levels has been expanded. In view of this, the active participation of all countries in the world cross-sectoral integration of disaster prevention technology research and development, in addition, the specialized field of disaster prevention technology, science and technology development, network integration technology, high-speed data transmission and information to support the establishment of mechanisms for disaster management The decision-making and cross-border global disaster information network building and other related technologies, has become the international anti-disaster science and technology development trends, this trend. Naturally a few years in Taiwan, people's lives and property losses caused by many problems related to natural disaster prevention and disaster prevention and the establishment of applications has become a very important. For FEWS_Taiwan, flood warning system developed by the Delft Hydraulics and introduced the Water Resources Agency (WRA), it provides those functionalities for users to modify contents to add the basins, regions, data sources, models and etc. Despite this advantage, version differences due to different users or different teams yet bring about the difficulties on synchronization and integration.At the same time in different research teams will also add different modes of meteorological and hydrological data. From the government perspective of WRA, the need to plan standard operation procedures for system integration demands that the effort for version control due to version differences must be cost down or yet canceled out. As for FEWS_Taiwan, this
Coherent Optical Propagation Properties Based on a Generalized Multi-Mode Optomechanical System
NASA Astrophysics Data System (ADS)
Chen, Hua-Jun; Fang, Xian-Wen; Chen, Chang-Zhao; Li, Yang; Tang, Xu-Dong
2017-03-01
A generalized three-modes optomechanical system is presented where two cavity modes driven by two-tone fields are coupled to a mechanical resonator. We find that two input probe lasers can be entirely absorbed by the mechanical resonator without inducing any energy output from any of the cavity modes termed as coherent perfect absorption. Furthermore, the input probe laser will transmit from one cavity to the other cavity without undergoing any energy loss which is termed as coherent perfect transmission under different parameter regimes. The origin and conditions that enable the phenomena to achieve are analysed, and potential applications in quantum information may be realized in all-optical domain based on these phenomena.
Bosonization and Strongly Correlated Systems
NASA Astrophysics Data System (ADS)
Gogolin, Alexander O.; Nersesyan, Alexander A.; Tsvelik, Alexei M.
2004-12-01
Preface; Acknowledgements; Part I. Technical Aspects of Bosonization: 1. A simple case of Bose-Fermi equivalence: Jordan-Wigner transformation; 2. One-dimensional fermions. States near the Fermi points; 3. Gaussian model. Lagrangian formulation; 4. Conformal symmetry and finite size effects; 5. Virasoro algebra; 6. Structure of Hilbert space in conformal theories; 7. Current (Kac-Moody) algebras: the first assault; 8. Relevant and irrelevant fields; 9. Bose-Einstein condensation in two dimensions; Beresinskii-Kosterlitz-Thouless transition; 10. The sine-Gordon model; 11. Spin S=1/2 Heisenberg-Ising chain; 12. Ising model; 13. More about WZNW model; 14. Non-Abelian bosonization; Part II. Application of the Bosonization Technique to Physical Models in (1+1)-Dimensions: 15. Interacting fermions with spin; 16. Spin-1/2 Tomonaga-Luttinger liquid; 17. Instabilities of Tomonaga-Luttinger liquid; 18. Interacting fermions with broken spin rotational symmetry; 19. What happens with Tomonaga-Luttinger liquid in three dimensions; 20. Two weakly coupled Tomonaga-Luttinger liquids; spinless case; 21. Spin liquids in one dimension: example of spin-ladders; 22. Spin-1/2 Heisenberg chain with alternating exchange; 23. Superconductivity in a doped spin liquid; 24. Edge states in quantum Hall effect; Part III. Single Impurity Problems: 25. Potential scattering; 26. X-ray edge problem (Fermi liquids); 27. Impurities in Tomonaga-Luttinger liquid; 28. Multi-channel Kondo problem; General Bibliography; Index.
NASA Technical Reports Server (NTRS)
Hindson, William S.
1987-01-01
A flight investigation was conducted to evaluate a multi-mode flight control system designed according to the most recent recommendations for handling qualities criteria for new military helicopters. The modes and capabilities that were included in the system are those considered necessary to permit divided-attention (single-pilot) lowspeed and hover operations near the ground in poor visibility conditions. Design features included mode-selection and mode-blending logic, the use of an automatic position-hold mode that employed precision measurements of aircraft position, and a hover display which permitted manually-controlled hover flight tasks in simulated instrument conditions. Pilot evaluations of the system were conducted using a multi-segment evaluation task. Pilot comments concerning the use of the system are provided, and flight-test data are presented to show system performance.
NASA Astrophysics Data System (ADS)
Sweeney, Michael; Spinazzola, Robert; Morrison, Donald; Macklin, Dennis; Marion, Jared
2011-06-01
Homeland security systems, special forces, unmanned aerial vehicles (UAV), and marine patrols require low cost, high performance, multi-mode visible through infrared (VIS-IR) wavelength optical systems to identify and neutralize potential threats that often arise at long ranges and under poor visibility conditions. Long range and wide spectral performance requirements favor reflective optical system design solutions. The limited field of view of such designs can be significantly enhanced by the use of catadioptric optical solutions that utilize molded or diamond point machined VIS-IR lenses downstream from reflective objective optics. A common optical aperture that services multiple modes of field-of-view, operating wavelength, and includes laser ranging and spotting, provides the highest utility and is most ideal for size and weight. Such a design also often requires fast, highly aspheric, reflective, refractive, and sometimes diffractive surfaces using high performance and aggressively light-weighted materials that demand the finest of manufacturing technologies. Visible wavelength performance sets the bar for component optical surface irregularity on the order of 20 nm RMS and surface finishes less than 3.0 nm RMS. Aluminum mirrors and structures can also be precision machined to yield "snap together alignment" or limited compensation assembly approaches to reduce cost and enhance interchangeability. Diamond point turning, die cast and investment cast mirror substrates and structures, computerized optical polishing, mirror replication, lens molding and other advanced manufacturing technologies can all be used to minimize the cost of this type of optical equipment. This paper discusses the tradeoffs among materials and process selection for catadioptric, multi-mode systems that are under development for a variety of DoD and Homeland Security applications. Several examples are profiled to illuminate the confluence of applicable design and manufacturing
Multi-Mode Broadband Patch Antenna
NASA Technical Reports Server (NTRS)
Romanofsky, Robert R. (Inventor)
2001-01-01
A multi-mode broad band patch antenna is provided that allows for the same aperture to be used at independent frequencies such as reception at 19 GHz and transmission at 29 GHz. Furthermore, the multi-mode broadband patch antenna provides a ferroelectric film that allows for tuning capability of the multi-mode broadband patch antenna over a relatively large tuning range. The alternative use of a semiconductor substrate permits reduced control voltages since the semiconductor functions as a counter electrode.
Boson mapping treatment of atoms-photon systems
Reboiro, M.
2007-02-12
A system which consists of A identical atoms, each of them having three atomic levels, and one optical photon is analyzed in terms of an algebraic approach. The symmetries exhibit by the model are used to construct an exact boson mapping of the Hamiltonian. The image-Hamiltonian reduces to a form which contains one boson and two atomic levels.
Object recognition through a multi-mode fiber
NASA Astrophysics Data System (ADS)
Takagi, Ryosuke; Horisaki, Ryoichi; Tanida, Jun
2017-04-01
We present a method of recognizing an object through a multi-mode fiber. A number of speckle patterns transmitted through a multi-mode fiber are provided to a classifier based on machine learning. We experimentally demonstrated binary classification of face and non-face targets based on the method. The measurement process of the experimental setup was random and nonlinear because a multi-mode fiber is a typical strongly scattering medium and any reference light was not used in our setup. Comparisons between three supervised learning methods, support vector machine, adaptive boosting, and neural network, are also provided. All of those learning methods achieved high accuracy rates at about 90% for the classification. The approach presented here can realize a compact and smart optical sensor. It is practically useful for medical applications, such as endoscopy. Also our study indicated a promising utilization of artificial intelligence, which has rapidly progressed, for reducing optical and computational costs in optical sensing systems.
Object recognition through a multi-mode fiber
NASA Astrophysics Data System (ADS)
Takagi, Ryosuke; Horisaki, Ryoichi; Tanida, Jun
2017-02-01
We present a method of recognizing an object through a multi-mode fiber. A number of speckle patterns transmitted through a multi-mode fiber are provided to a classifier based on machine learning. We experimentally demonstrated binary classification of face and non-face targets based on the method. The measurement process of the experimental setup was random and nonlinear because a multi-mode fiber is a typical strongly scattering medium and any reference light was not used in our setup. Comparisons between three supervised learning methods, support vector machine, adaptive boosting, and neural network, are also provided. All of those learning methods achieved high accuracy rates at about 90% for the classification. The approach presented here can realize a compact and smart optical sensor. It is practically useful for medical applications, such as endoscopy. Also our study indicated a promising utilization of artificial intelligence, which has rapidly progressed, for reducing optical and computational costs in optical sensing systems.
MAPLE Procedures For Boson Fields System On Curved Space - Time
Murariu, Gabriel
2007-04-23
Systems of interacting boson fields are an important subject in the last years. From the problem of dark matter to boson stars' study, boson fields are involved. In the general configuration, it is considered a Klein-Gordon-Maxwell-Einstein fields system for a complex scalar field minimally coupled to a gravitational one. The necessity of studying a larger number of space-time configurations and the huge volume of computations for each particular situation are some reasons for building a MAPLE procedures set for this kind of systems.
Slave boson theories of correlated electron systems
Woelfle, P.
1995-05-01
Slave boson theories of various models of correlated fermions are critically reviewed and several new results are presented. In the example of the Anderson impurity model the limitations of slave boson mean field theory are discussed. Self-consistent conserving approximations are compared with results obtained from the numerical renormalization group. The gauge field theory of the t-J-model is considered in the quasistatic approximation. It is shown that weak localization effects can give valuable information on the existence of gauge fields. Applications of the slave-boson approach due to Kotliar and Ruckenstein to the Hubbard model are also discussed.
Kinetic Monte Carlo approach to nonequilibrium bosonic systems
NASA Astrophysics Data System (ADS)
Liew, T. C. H.; Flayac, H.; Poletti, D.; Savenko, I. G.; Laussy, F. P.
2017-09-01
We consider the use of a kinetic Monte Carlo approach for the description of nonequilibrium bosonic systems, taking nonresonantly excited exciton-polariton condensates and bosonic cascade lasers as examples. In the former case, the considered approach allows the study of the cross-over between incoherent and coherent regimes, which represents the formation of a quasicondensate that forms purely from the action of energy relaxation processes rather than interactions between the condensing particles themselves. In the latter case, we show theoretically that a bosonic cascade can develop an output coherent state.
Nonclassical distance in multimode bosonic systems
NASA Astrophysics Data System (ADS)
Nair, Ranjith
2017-06-01
We revisit the notion of nonclassical distance of states of bosonic quantum systems introduced in Phys. Rev. A 35, 725 (1987), 10.1103/PhysRevA.35.725 in a general multimode setting. After reviewing its definition, we establish some of its general properties. We obtain new upper and lower bounds on the nonclassical distance in terms of the supremum of the Husimi function of the state. Considering several examples, we elucidate the cases for which our lower bound is tight, which include the multimode number states and a class of multimode NOON states. The latter provide examples of states of definite photon number n ≥2 whose nonclassical distance can be made arbitrarily close to the upper limit of 1 by increasing the number of modes. We show that the nonclassical distance of the even and odd Schrödinger cat states is bounded away from unity regardless of how macroscopic the superpositions are, and that the nonclassical distance is not necessarily monotonically increasing with respect to macroscopicity.
Emergent Fermi sea in a system of interacting bosons
NASA Astrophysics Data System (ADS)
Wu, Ying-Hai; Jain, J. K.
2015-06-01
An understanding of the possible ways in which interactions can produce fundamentally new emergent many-body states is a central problem of condensed-matter physics. We ask if a Fermi sea can arise in a system of bosons subject to contact interaction. Based on exact diagonalization studies and variational wave functions, we predict that such a state is likely to occur when a system of two-component bosons in two dimensions, interacting via a species-independent contact interaction, is exposed to a synthetic magnetic field of strength that corresponds to a filling factor of unity. The fermions forming the SU(2) singlet Fermi sea are bound states of bosons and quantized vortices, formed as a result of the repulsive interaction between bosons in the lowest Landau level.
NASA Astrophysics Data System (ADS)
Dalton, B. J.; Goold, J.; Garraway, B. M.; Reid, M. D.
2017-02-01
These two accompanying papers are concerned with entanglement for systems of identical massive bosons and the relationship to spin squeezing and other quantum correlation effects. The main focus is on two mode entanglement, but multi-mode entanglement is also considered. The bosons may be atoms or molecules as in cold quantum gases. The previous paper I dealt with the general features of quantum entanglement and its specific definition in the case of systems of identical bosons. Entanglement is a property shared between two (or more) quantum sub-systems. In defining entanglement for systems of identical massive particles, it was concluded that the single particle states or modes are the most appropriate choice for sub-systems that are distinguishable, that the general quantum states must comply both with the symmetrization principle and the super-selection rules (SSR) that forbid quantum superpositions of states with differing total particle number (global SSR compliance). Further, it was concluded that (in the separable states) quantum superpositions of sub-system states with differing sub-system particle number (local SSR compliance) also do not occur. The present paper II determines possible tests for entanglement based on the treatment of entanglement set out in paper I. Several inequalities involving variances and mean values of operators have been previously proposed as tests for entanglement between two sub-systems. These inequalities generally involve mode annihilation and creation operators and include the inequalities that define spin squeezing. In this paper, spin squeezing criteria for two mode systems are examined, and spin squeezing is also considered for principle spin operator components where the covariance matrix is diagonal. The proof, which is based on our SSR compliant approach shows that the presence of spin squeezing in any one of the spin components requires entanglement of the relevant pair of modes. A simple Bloch vector test for
Measure of tripartite entanglement in bosonic and fermionic systems
Buscemi, Fabrizio
2011-08-15
We describe an efficient theoretical criterion suitable for the evaluation of the tripartite entanglement of any mixed three-boson or three-fermion state, based on the notion of the entanglement of particles for bipartite systems of identical particles. Our approach allows one to quantify the accessible number of quantum correlations in the systems without any violation of the local particle number superselection rule. A generalization of the tripartite negativity is here applied to some correlated systems including the continuous-time quantum walks of identical particles (for both bosons and fermions) and compared with other criteria recently proposed in the literature. Our results show the dependence of the entanglement dynamics upon the quantum statistics: The bosonic bunching results in a low number of quantum correlations while Fermi-Dirac statistics allows for higher values of the entanglement.
On the control of spin-boson systems
Boscain, Ugo; Mason, Paolo; Panati, Gianluca; Sigalotti, Mario
2015-09-15
In this paper, we study the so-called spin-boson system, namely, a two-level system in interaction with a distinguished mode of a quantized bosonic field. We give a brief description of the controlled Rabi and Jaynes–Cummings models and we discuss their appearance in the mathematics and physics literature. We then study the controllability of the Rabi model when the control is an external field acting on the bosonic part. Applying geometric control techniques to the Galerkin approximation and using perturbation theory to guarantee non-resonance of the spectrum of the drift operator, we prove approximate controllability of the system, for almost every value of the interaction parameter.
Numerical studies of a model fermion-boson system
NASA Astrophysics Data System (ADS)
Cheng, T.; Gospodarczyk, E. R.; Su, Q.; Grobe, R.
2010-02-01
We study the spectral and dynamical properties of a simplified model system of interacting fermions and bosons. The spatial discretization and an effective truncation of the Hilbert space permit us to compute the distribution of the bare fermions and bosons in the energy eigenstates of the coupled system. These states represent the physical particles and are used to examine the validity of the analytical predictions by perturbation theory and by the Greenberg-Schweber approximation that assumes all fermions are at rest. As an example of our numerical framework, we examine how a bare electron can trigger the creation of a cloud of virtual bosons around. We relate this cloud to the properties of the associated energy eigenstates.
NASA Astrophysics Data System (ADS)
Das, Bankim Chandra; Bhattacharyya, Dipankar; Das, Arpita; Chakrabarti, Shrabana; De, Sankar
2016-12-01
We report here simultaneous experimental observation of Electromagnetically Induced Transparency (EIT) and Electromagnetically Induced Absorption (EIA) in a multi-level V-type system in D2 transition of 87Rb, i.e., F =2 →F' with a strong pump and a weak probe beam. We studied the probe spectrum by locking the probe beam to the transition F =2 →F'=2 while the pump is scanned from F =2 →F' . EIA is observed for the open transition (F =2 →F'=2 ) whereas EIT is observed in the closed transition (F =2 →F'=3 ). Sub natural line-width is observed for the EIA. To simulate the observed spectra theoretically, Liouville equation for the three-level V-type system is solved analytically with a multi-mode approach for the density matrix elements. We assumed both the pump and the probe beams can couple the excited states. A multi-mode approach for the coherence terms facilitates the study of all the frequency contributions due to the pump and the probe fields. Since the terms contain higher harmonics of the pump and the probe frequencies, we expressed them in Fourier transformed forms. To simulate the probe spectrum, we have solved inhomogeneous difference equations for the coherence terms using the Green's function technique and continued fraction theory. The experimental line-widths of the EIT and the EIA are compared with our theoretical model. Our system can be useful in optical switching applications as it can be precisely tuned to render the medium opaque and transparent simultaneously.
Quantum entanglement for systems of identical bosons: I. General features
NASA Astrophysics Data System (ADS)
Dalton, B. J.; Goold, J.; Garraway, B. M.; Reid, M. D.
2017-02-01
These two accompanying papers are concerned with two mode entanglement for systems of identical massive bosons and the relationship to spin squeezing and other quantum correlation effects. Entanglement is a key quantum feature of composite systems in which the probabilities for joint measurements on the composite sub-systems are no longer determined from measurement probabilities on the separate sub-systems. There are many aspects of entanglement that can be studied. This two-part review focuses on the meaning of entanglement, the quantum paradoxes associated with entangled states, and the important tests that allow an experimentalist to determine whether a quantum state—in particular, one for massive bosons is entangled. An overall outcome of the review is to distinguish criteria (and hence experiments) for entanglement that fully utilize the symmetrization principle and the super-selection rules that can be applied to bosonic massive particles. In the first paper (I), the background is given for the meaning of entanglement in the context of systems of identical particles. For such systems, the requirement is that the relevant quantum density operators must satisfy the symmetrization principle and that global and local super-selection rules prohibit states in which there are coherences between differing particle numbers. The justification for these requirements is fully discussed. In the second quantization approach that is used, both the system and the sub-systems are modes (or sets of modes) rather than particles, particles being associated with different occupancies of the modes. The definition of entangled states is based on first defining the non-entangled states—after specifying which modes constitute the sub-systems. This work mainly focuses on the two mode entanglement for massive bosons, but is put in the context of tests of local hidden variable theories, where one may not be able to make the above restrictions. The review provides the detailed
Thermal Radiation Laws of a q-deformed Boson System in m Dimensions
NASA Astrophysics Data System (ADS)
Zeng, QiJun; Ge, Jing; Luo, Hao; Luo, YongSong
2017-09-01
Within the theoretical framework of multidimensional space and q bosons, we generalize our hypothesis of regarding the CMBR as the radiation of q bosons, and investigate the thermal radiation laws of a q boson system in m dimensions. Utilizing the new radiation laws, we make a numerical calculation and the results show that these new laws have some special features. We consider that this work may provide more insight into the theory of q bosons and the study on the CMBR.
Dynamics of open bosonic quantum systems in coherent state representation
Dalvit, D. A. R.; Berman, G. P.; Vishik, M.
2006-01-15
We consider the problem of decoherence and relaxation of open bosonic quantum systems from a perspective alternative to the standard master equation or quantum trajectories approaches. Our method is based on the dynamics of expectation values of observables evaluated in a coherent state representation. We examine a model of a quantum nonlinear oscillator with a density-density interaction with a collection of environmental oscillators at finite temperature. We derive the exact solution for dynamics of observables and demonstrate a consistent perturbation approach.
Geometric fluctuation theorem for a spin-boson system
NASA Astrophysics Data System (ADS)
Watanabe, Kota L.; Hayakawa, Hisao
2017-08-01
We derive an extended fluctuation theorem for geometric pumping of a spin-boson system under periodic control of environmental temperatures by using a Markovian quantum master equation. We obtain the current distribution, the average current, and the fluctuation in terms of the Monte Carlo simulation. To explain the results of our simulation we derive an extended fluctuation theorem. This fluctuation theorem leads to the fluctuation dissipation relations but the absence of the conventional reciprocal relation.
Universal Behavior of Few-Boson Systems Using Potential Models
NASA Astrophysics Data System (ADS)
Kievsky, A.; Viviani, M.; Álvarez-Rodríguez, R.; Gattobigio, M.; Deltuva, A.
2017-03-01
The universal behavior of a three-boson system close to the unitary limit is encoded in a simple dependence of many observables in terms of few parameters. For example the product of the three-body parameter κ _* and the two-body scattering length a, κ _* a depends on the angle ξ defined by E_3/E_2=tan ^2ξ . A similar dependence is observed in the ratio a_{AD}/a with a_{AD} the boson-dimer scattering length. We use a two-parameter potential to determine this simple behavior and, as an application, to compute a_{AD} for the case of three ^4He atoms.
Even-odd entanglement in boson and spin systems
NASA Astrophysics Data System (ADS)
Rossignoli, R.; Canosa, N.; Matera, J. M.
2011-04-01
We examine the entanglement entropy of the even half of a translationally invariant finite chain or lattice in its ground state. This entropy measures the entanglement between the even and odd halves (each forming a “comb” of n/2 sites) and can be expected to be extensive for short-range couplings away from criticality. We first consider bosonic systems with quadratic couplings, where analytic expressions for arbitrary dimensions can be provided. The bosonic treatment is then applied to finite spin chains and arrays by means of the random-phase approximation. Results for first-neighbor anisotropic XY couplings indicate that, while at strong magnetic fields this entropy is strictly extensive, at weak fields important deviations arise, stemming from parity-breaking effects and the presence of a factorizing field (in the vicinity of which it becomes size-independent and identical to the entropy of a contiguous half). Exact numerical results for small spin s chains are shown to be in agreement with the bosonic random-phase approximation prediction.
Hidden supersymmetry in quantum bosonic systems
Correa, Francisco Plyushchay, Mikhail S.
2007-10-15
We show that some simple well-studied quantum mechanical systems without fermion (spin) degrees of freedom display, surprisingly, a hidden supersymmetry. The list includes the bound state Aharonov-Bohm, the Dirac delta and the Poeschl-Teller potential problems, in which the unbroken and broken N = 2 supersymmetry of linear and nonlinear (polynomial) forms is revealed.
Ghost free systems with coexisting bosons and fermions
NASA Astrophysics Data System (ADS)
Kimura, Rampei; Sakakihara, Yuki; Yamaguchi, Masahide
2017-08-01
We study the coexistence system of both bosonic and fermionic degrees of freedom. Even if a Lagrangian does not include higher derivatives, fermionic ghosts exist. For a Lagrangian with up to first derivatives, we find the fermionic ghost free condition in Hamiltonian analysis, which is found to be the same as requiring that the equations of motion of fermions be first order in Lagrangian formulation. When fermionic degrees of freedom are present, the uniqueness of time evolution is not guaranteed a priori because of the Grassmann property. We confirm that the additional condition, which is introduced to close Hamiltonian analysis, also ensures the uniqueness of the time evolution of the system.
Intraband and interband conductivity in systems of strongly interacting bosons
NASA Astrophysics Data System (ADS)
Grygiel, B.; Patucha, K.; Zaleski, T. A.
2017-09-01
Motivated by recent experimental progress on measuring various correlation functions in systems of ultracold atoms in optical lattices, we study properties of the Bose-Hubbard model in external synthetic magnetic field to describe transport phenomena in a multiband strongly interacting bosonic systems. We calculate the conductivity both in the Mott insulator and superfluid phases and investigate its two main contributions: intra- and interband. It appears that the interband processes dominate the transport properties by at least an order of magnitude. Also, at finite temperatures, additional transport channels appear due to coupling of the thermally excited particles or holes to the external field.
Curtiss, J.A.; Jahelka, J.R.
1995-08-11
Brookhaven National Laboratory (BNL) recently developed a two-component system for use during remote inspections. The system consists of a mobile unit with television cameras and other equipment and a stationary base station. A variety of signals must be continually transmitted between the two system components as the mobile unit is moved from the location to another. Two channels of broadband (10MHz) NTSC video are transmitted from the mobile unit to the base station, and a bi-directional ``talk set`` provides audio communication between personnel at each location. In addition, several channels of RS-232 are required to support present and future instruments used at the mobile unit and controlled by personnel at the base station. Brookhaven developed a mobile unit which communicated with a base station over a 2-fiber multimode fiber optic cable. One of the design requirements was maintaining constant communication with the base station during the time the mobile unit was moved about. To provide uninterrupted communications, deployment of the 1-km long fiber optic cable was initially performed with a ``spinning reel`` mechanism. The spinning reel mechanism proved to be mechanically unsuitable, and so the cable deployment mechanism was redesigned to spool the cable off the reel. The requirement for uninterrupted communications required a two-channel fiber optic rotary joint in the design. Incorporation of the rotary joint into the design is described, and appropriate reference material is included.
Multi-mode reliability-based design of horizontal curves.
Essa, Mohamed; Sayed, Tarek; Hussein, Mohamed
2016-08-01
Recently, reliability analysis has been advocated as an effective approach to account for uncertainty in the geometric design process and to evaluate the risk associated with a particular design. In this approach, a risk measure (e.g. probability of noncompliance) is calculated to represent the probability that a specific design would not meet standard requirements. The majority of previous applications of reliability analysis in geometric design focused on evaluating the probability of noncompliance for only one mode of noncompliance such as insufficient sight distance. However, in many design situations, more than one mode of noncompliance may be present (e.g. insufficient sight distance and vehicle skidding at horizontal curves). In these situations, utilizing a multi-mode reliability approach that considers more than one failure (noncompliance) mode is required. The main objective of this paper is to demonstrate the application of multi-mode (system) reliability analysis to the design of horizontal curves. The process is demonstrated by a case study of Sea-to-Sky Highway located between Vancouver and Whistler, in southern British Columbia, Canada. Two noncompliance modes were considered: insufficient sight distance and vehicle skidding. The results show the importance of accounting for several noncompliance modes in the reliability model. The system reliability concept could be used in future studies to calibrate the design of various design elements in order to achieve consistent safety levels based on all possible modes of noncompliance.
Interactive multi-mode blade impact analysis
NASA Technical Reports Server (NTRS)
Alexander, A.; Cornell, R. W.
1978-01-01
The theoretical methodology used in developing an analysis for the response of turbine engine fan blades subjected to soft-body (bird) impacts is reported, and the computer program developed using this methodology as its basis is described. This computer program is an outgrowth of two programs that were previously developed for the purpose of studying problems of a similar nature (a 3-mode beam impact analysis and a multi-mode beam impact analysis). The present program utilizes an improved missile model that is interactively coupled with blade motion which is more consistent with actual observations. It takes into account local deformation at the impact area, blade camber effects, and the spreading of the impacted missile mass on the blade surface. In addition, it accommodates plate-type mode shapes. The analysis capability in this computer program represents a significant improvement in the development of the methodology for evaluating potential fan blade materials and designs with regard to foreign object impact resistance.
Forward scattering approximation and bosonization in integer quantum Hall systems
Rosenau da Costa, M. Westfahl, H.; Caldeira, A.O.
2008-03-15
In this work, we present a model and a method to study integer quantum Hall (IQH) systems. Making use of the Landau levels structure we divide these two-dimensional systems into a set of interacting one-dimensional gases, one for each guiding center. We show that the so-called strong field approximation, used by Kallin and Halperin and by MacDonald, is equivalent, in first order, to a forward scattering approximation and analyze the IQH systems within this approximation. Using an appropriate variation of the Landau level bosonization method we obtain the dispersion relations for the collective excitations and the single-particle spectral functions. For the bulk states, these results evidence a behavior typical of non-normal strongly correlated systems, including the spin-charge splitting of the single-particle spectral function. We discuss the origin of this behavior in the light of the Tomonaga-Luttinger model and the bosonization of two-dimensional electron gases.
Floquet Topological Order in Interacting Systems of Bosons and Fermions
NASA Astrophysics Data System (ADS)
Harper, Fenner; Roy, Rahul
2017-03-01
Periodically driven noninteracting systems may exhibit anomalous chiral edge modes, despite hosting bands with trivial topology. We find that these drives have surprising many-body analogs, corresponding to class A, which exhibit anomalous charge and information transport at the boundary. Drives of this form are applicable to generic systems of bosons, fermions, and spins, and may be characterized by the anomalous unitary operator that acts at the edge of an open system. We find that these operators are robust to all local perturbations and may be classified by a pair of coprime integers. This defines a notion of dynamical topological order that may be applied to general time-dependent systems, including many-body localized phases or time crystals.
Mode Launcher Design for the Multi-moded DLDS
Li, Zenghai
2003-04-30
The DLDS (Delay Line Distribution System) power delivery system proposed by KEK combines several klystrons to obtain the high peak power required to drive a TeV scale linear collider. In this system the combined klystron output is subdivided into shorter pulses by proper phasing of the sources, and each subpulse is delivered to various accelerator sections via separate waveguides. A cost-saving improvement suggested by SLAC is to use a single multimoded waveguide to deliver the power of all the subpulses. This scheme requires a mode launcher that can deliver each subpulse by way of a different waveguide mode through selective phasing of the sources when combining their power. We present a compact design for such a mode launcher that converts the power from four rectangular waveguide feeds to separate modes in a multi-moded circular guide through coupling slots. Such a design has been simulated and found to satisfy the requirements for high efficiency and low surface fields.
Effective field theory for few-boson systems
NASA Astrophysics Data System (ADS)
Bazak, Betzalel; Eliyahu, Moti; van Kolck, Ubirajara
2016-11-01
We study universal bosonic few-body systems within the framework of effective field theory at leading order (LO). We calculate binding energies of systems of up to six particles and the atom-dimer scattering length. Convergence to the limit of zero-range two- and three-body interactions is shown, indicating that no additional few-body interactions need to be introduced at LO. Generalizations of the Tjon line are constructed, showing correlations between few-body binding energies and the binding energy of the trimer, for a given dimer energy. As a specific example, we implement our theory for 4He atomic systems and show that the results are in surprisingly good agreement with those of sophisticated 4He-4He potentials. Potential implications for the convergence of the EFT expansion are discussed.
Multi-mode ultrasonic welding control and optimization
Tang, Jason C.H.; Cai, Wayne W
2013-05-28
A system and method for providing multi-mode control of an ultrasonic welding system. In one embodiment, the control modes include the energy of the weld, the time of the welding process and the compression displacement of the parts being welded during the welding process. The method includes providing thresholds for each of the modes, and terminating the welding process after the threshold for each mode has been reached, the threshold for more than one mode has been reached or the threshold for one of the modes has been reached. The welding control can be either open-loop or closed-loop, where the open-loop process provides the mode thresholds and once one or more of those thresholds is reached the welding process is terminated. The closed-loop control provides feedback of the weld energy and/or the compression displacement so that the weld power and/or weld pressure can be increased or decreased accordingly.
Bose-Einstein condensation in low dimensional systems with deformed bosons
NASA Astrophysics Data System (ADS)
Algin, Abdullah; Olkun, Ali
2017-08-01
We study the low and high temperature thermostatistical properties of a deformed boson gas constructed by the bosonic intermediate-statistics particles confined in low spatial dimensions. Many of the deformed thermodynamical functions of the system such as internal energy and entropy are investigated by means of some elements of the Fibonacci calculus. Particular emphasis is given to a careful analysis on low dimensional systems of such deformed bosons, and the conditions under which the Bose-Einstein condensation would occur in such systems are discussed. We show that low dimensional systems with deformed bosons exhibit the Bose-Einstein condensation for values of the model deformation parameters (p , q) greater than one. We also study possible anyonic behavior of the model for high temperatures. The results obtained in this work reveal that the present deformed boson gas model can be used for modeling nonlinear behavior of systems with quasiparticles encountered in several areas of research particularly in quantum science.
Multiconfigurational time-dependent Hartree method for bosons: Many-body dynamics of bosonic systems
NASA Astrophysics Data System (ADS)
Alon, Ofir E.; Streltsov, Alexej I.; Cederbaum, Lorenz S.
2008-03-01
The evolution of Bose-Einstein condensates is amply described by the time-dependent Gross-Pitaevskii mean-field theory which assumes all bosons to reside in a single time-dependent one-particle state throughout the propagation process. In this work, we go beyond mean field and develop an essentially exact many-body theory for the propagation of the time-dependent Schrödinger equation of N interacting identical bosons. In our theory, the time-dependent many-boson wave function is written as a sum of permanents assembled from orthogonal one-particle functions, or orbitals, where both the expansion coefficients and the permanents (orbitals) themselves are time-dependent and fully determined according to a standard time-dependent variational principle. By employing either the usual Lagrangian formulation or the Dirac-Frenkel variational principle we arrive at two sets of coupled equations of motion, one for the orbitals and one for the expansion coefficients. The first set comprises of first-order differential equations in time and nonlinear integrodifferential equations in position space, whereas the second set consists of first-order differential equations with time-dependent coefficients. We call our theory multiconfigurational time-dependent Hartree for bosons, or MCTDHB(M) , where M specifies the number of time-dependent orbitals used to construct the permanents. Numerical implementation of the theory is reported and illustrative numerical examples of many-body dynamics of trapped Bose-Einstein condensates are provided and discussed. The convergence of the method with a growing number M of orbitals is demonstrated in a specific example of four interacting bosons in a double well.
Virtual monopoles in a bosonic atom-diatomic-molecule system
NASA Astrophysics Data System (ADS)
Li, Sheng-Chang; Fu, Li-Bin; Liu, Jie
2014-02-01
We investigate the virtual monopoles in an ultracold bosonic atom-diatomic-molecule system with a three-level second-quantized model. In the quantum theory, we show that the monopole field of the ground state does not have a spherical symmetry. We calculate the monopole charge and find that it is an integer multiple of the elementary charge g0=1/2. This multiple exactly reflects the degeneracy properties of the ground state and strongly depends on the total particle number and the atom-number imbalance between two atomic species. In the mean-field limit, we illustrate that the system can create continuous monopole charges in the case of heteronuclear molecules. The underlying mechanism associated with the degeneracy properties and the application related to the quantum phase transition of the monopoles are briefly discussed as well.
Monte Carlo Ground State Energy for Trapped Boson Systems
NASA Astrophysics Data System (ADS)
Rudd, Ethan; Mehta, N. P.
2012-06-01
Diffusion Monte Carlo (DMC) and Green's Function Monte Carlo (GFMC) algorithms were implemented to obtain numerical approximations for the ground state energies of systems of bosons in a harmonic trap potential. Gaussian pairwise particle interactions of the form V0e^-|ri-rj|^2/r0^2 were implemented in the DMC code. These results were verified for small values of V0 via a first-order perturbation theory approximation for which the N-particle matrix element evaluated to N2 V0(1 + 1/r0^2)^3/2. By obtaining the scattering length from the 2-body potential in the perturbative regime (V0φ 1), ground state energy results were compared to modern renormalized models by P.R. Johnson et. al, New J. Phys. 11, 093022 (2009).
Exploring quantum phase slips in 1D bosonic systems
NASA Astrophysics Data System (ADS)
Abbate, Simona Scaffidi; Gori, Lorenzo; Inguscio, Massimo; Modugno, Giovanni; D'Errico, Chiara
2017-07-01
Quantum phase slips, i.e., the primary excitations in one-dimensional superfluids at low temperature, have been well characterized in most condensed-matter systems, with the notable exception of ultracold quantum gases. Here we present our experimental investigation of the dissipation in one-dimensional Bose superfluids flowing along a periodic potential, which show signatures of the presence of quantum phase slips. In particular, by controlling the velocity of the superfluid and the interaction between the bosons we are apparently able to drive a crossover from a regime of thermal phase slips into a regime of quantum phase slips. Achieving a good control of quantum phase slips in ultracold quantum gases requires to keep under control other phenomena such as the breaking of superfluidity at the critical velocity or the appearance of a Mott insulator in the strongly correlated regime. Here we show our current results in these directions.
Non-ideal boson system in the Gaussian approximation
Tommasini, P.R.; de Toledo Piza, A.F.
1997-01-01
We investigate ground-state and thermal properties of a system of non-relativistic bosons interacting through repulsive, two-body interactions in a self-consistent Gaussian mean-field approximation which consists in writing the variationally determined density operator as the most general Gaussian functional of the quantized field operators. Finite temperature results are obtained in a grand canonical framework. Contact is made with the results of Lee, Yang, and Huang in terms of particular truncations of the Gaussian approximation. The full Gaussian approximation supports a free phase or a thermodynamically unstable phase when contact forces and a standard renormalization scheme are used. When applied to a Hamiltonian with zero range forces interpreted as an effective theory with a high momentum cutoff, the full Gaussian approximation generates a quasi-particle spectrum having an energy gap, in conflict with perturbation theory results. {copyright} 1997 Academic Press, Inc.
Review on the Recent Development of Multi-mode Combined Detonation Engine
NASA Astrophysics Data System (ADS)
Jin, Le; Fan, Wei; Wang, Ke; Gao, Zhan
2013-09-01
In the next few decades, the development of hypersonic aircrafts will be the priority of national defense strategy of many countries, and the significance of the propulsion system applied on the aircraft is self-evident. Hypersonic aircrafts require propulsion devices that can be used independently in a wide range of Mach numbers and flight envelop, however, there have been no such propulsion systems up to now. The multi-mode combined detonation engine, which consists of four modes, is a novel propulsion concept proposed at the beginning of this century for potential application on hypersonic cruise or space access. The multi-mode combined detonation engine is a promising propulsion system which can be used independently in a wide range of Mach numbers and flight envelop. Recently, many countries attach much importance to the research of multi-mode combined detonation engine and great progress has been achieved. This paper attempts to provide an overview of the recent advances in the multi-mode combined detonation engine, and the major progress for each mode is detailed introduced. Nevertheless, there is still a need to pay more attention to the existing problems in the future.
An SMS (single mode - multi mode - single mode) fiber structure for vibration sensing
NASA Astrophysics Data System (ADS)
Waluyo, T. B.; Bayuwati, D.
2017-04-01
We describe an SMS (single mode - multi mode - single mode) fiber structure to be used in a vibration sensing system. The fiber structure was fabricated by splicing a section (about 300 mm in length) of a step index multi mode fiber between two single mode fibers obtained from a communication grade fiber patchcord. Interference between higher order modes occurs while light from a narrow band light source travels along the multi mode fiber. When the multi mode fiber vibrates, the refractive index profile is changed because of the photo-elastics effect and the amplitude of the interference pattern is changed accordingly. To simulate a vibrating structure we used a loudspeaker to vibrate a wooden table. By using a digital oscilloscope, we recorded and analysed the vibrating signals obtained from the SMS fiber structure as well as from a GS-32CT geophone for referencing. We observed that this SMS fiber structure was potential to be used in a vibration sensing system with a measurement range from 30 to 180 Hz with inherent optical fiber sensor advantages such as light weight, immune to electromagnetic interference, and no electricity in the sensing part.
NASA Astrophysics Data System (ADS)
Aleixo, A. N. F.; Balantekin, A. B.
2014-08-01
We consider the minimal bosonization realization of supersymmetric shape-invariant systems where generalized supercharge operators are constructed using the partner supersymmetric operators, the parameter potential translation formalism and the reflection operator. We obtain the solution of the eigenvalue equation and study the quantum dynamics of the supersymmetric system including terms in the Hamiltonian which are constructed using the combination of the bosonized supercharge operators. The connections between the bosonized supersymmetric formalism, the Bose-Fermi transformation and the generalization of the R-deformed Heisenberg algebra are discussed. As an illustration, we apply the generalized formalism for the case of the trigonometric Rosen-Morse potential.
Sparse reconstruction of blade tip-timing signals for multi-mode blade vibration monitoring
NASA Astrophysics Data System (ADS)
Lin, Jun; Hu, Zheng; Chen, Zhong-Sheng; Yang, Yong-Min; Xu, Hai-Long
2016-12-01
Severe blade vibrations may reduce the useful life of the high-speed blade. Nowadays, non-contact measurement using blade tip-timing (BTT) technology is becoming promising in blade vibration monitoring. However, blade tip-timing signals are typically under-sampled. How to extract characteristic features of unknown multi-mode blade vibrations by analyzing these under-sampled signals becomes a big challenge. In this paper, a novel BTT analysis method for reconstructing unknown multi-mode blade vibration signals is proposed. The method consists of two key steps. First, a sparse representation (SR) mathematical model for sparse blade tip-timing signals is built. Second, a multi-mode blade vibration reconstruction algorithm is proposed to solve this SR problem. Experiments are carried out to validate the feasibility of the proposed method. The main advantage of this method is its ability to reconstruct unknown multi-mode blade vibration signals with high accuracy. The minimal requirements of probe number are also presented to provide guidelines for BTT system design.
Quantum criticality of bosonic systems with the Lifshitz dispersion
NASA Astrophysics Data System (ADS)
Wu, Jianda; Zhou, Fei; Wu, Congjun
2017-08-01
We study a novel type of quantum criticality of the Lifshitz φ4 theory below the upper critical dimension du=z +dc=8 , where the dynamic critical exponent z =4 and the spatial upper critical dimension dc=4 . Two fixed points, one Gaussian and the other non-Gaussian, are identified with zero and finite interaction strengths, respectively. At zero temperature the particle density exhibits different power-law dependences on the chemical potential in the weak- and strong-interaction regions. At finite temperatures, critical behaviors in the quantum disordered region are mainly controlled by the chemical potential. In contrast, in the quantum critical region critical scalings are determined by temperature. The scaling ansatz remains valid in the strong-interaction limit for the chemical potential, correlation length, and particle density, while it breaks down in the weak-interaction one. Approaching the upper critical dimension, physical quantities develop logarithmic dependence on dimensionality in the strong-interaction region. These results are applied to spin-orbit coupled bosonic systems, leading to predictions testable by future experiments.
Quantum rotor theory of systems of spin-2 bosons
NASA Astrophysics Data System (ADS)
Payrits, Matjaž; Barnett, Ryan
2016-08-01
We consider quantum phases of tightly confined spin-2 bosons in an external field under the presence of rotationally invariant interactions. Generalizing previous treatments, we show how this system can be mapped onto a quantum rotor model. Within the rotor framework, low-energy excitations about fragmented states, which cannot be accessed within standard Bogoliubov theory, can be obtained. In the spatially extended system in the thermodynamic limit there exists a mean field ground-state degeneracy between a family of nematic states for appropriate interaction parameters. It has been established that quantum fluctuations lift this degeneracy through the mechanism of order by disorder and select either a uniaxial or square-biaxial ground state. On the other hand, in the full quantum treatment of the analogous single-spatial-mode problem with finite-particle number, it is known that, due to symmetry-restoring fluctuations, there is a unique ground state across the entire nematic region of the phase diagram. Within the established rotor framework, we investigate the possible quantum phases under the presence of a quadratic Zeeman field, a problem which has previously received little attention. By investigating wave-function overlaps, we do not find any signatures of the order-by-disorder phenomenon which is present in the continuum case. Motivated by this, we consider an alternative external potential which breaks less symmetry than the quadratic Zeeman field. For this case, we do find the phenomenon of order by disorder in the fully quantum system. This is established within the rotor framework and with exact diagonalization.
Lowering of Boson-Fermion System Energy with a Gapped Cooper Resonant-Pair Dispersion Relation
NASA Astrophysics Data System (ADS)
Mamedov, T. A.; de Llano, M.
2007-09-01
Applying two-time Green-function techniques to the Friedberg-T.D. Lee phenomenological Hamiltonian of a many-fermion system, it is shown that positive-energy resonant bosonic pairs associated with four-fermion excitations above the Fermi sea are energetically lower in a ground-state that is a mixture of two coexisting and dynamically interacting many-particle subsystems: a) unpaired fermions and b) composite bosons. It is argued that an interaction between free fermions and bosons excited above the Fermi sea in the mixture, namely, the continuous processes of pair-formation from, and disintegration into, two unpaired electrons, results in a substantially lowering the total system energy. The positive-energy composite bosons begin to appear incoherently below a de-pairing temperature T* as their coupling- and temperature-dependent number density gradually increases from zero. This leads quite naturally to the pseudogap phenomenon observed in high-Tc cuprates
Lowering of Boson-Fermion System Energy with a Gapped Cooper Resonant-Pair Dispersion Relation
NASA Astrophysics Data System (ADS)
Mamedov, T. A.; de Llano, M.
Applying two-time Green-function techniques to the Friedberg-T.D. Lee phenomenological Hamiltonian of a many-fermion system, it is shown that positive-energy resonant bosonic pairs associated with four-fermion excitations above the Fermi sea are energetically lower in a ground-state that is a mixture of two coexisting and dynamically interacting many-particle subsystems: a) unpaired fermions and b) composite bosons. It is argued that an interaction between free fermions and bosons excited above the Fermi sea in the mixture, namely, the continuous processes of pair-formation from, and disintegration into, two unpaired electrons, results in a substantially lowering the total system energy. The positive-energy composite bosons begin to appear incoherently below a depairing temperature T* as their coupling- and temperature-dependent number density gradually increases from zero. This leads quite naturally to the pseudogap phenomenon observed in high-Tc cuprates.
Semiclassical solitons in strongly correlated systems of ultracold bosonic atoms in optical lattices
Demler, Eugene; Maltsev, Andrei
2011-07-15
Highlights: > Dynamics of their formation in strongly correlated systems of ultracold bosonic atoms in optical lattices. > Regime of very strong interactions between atoms, the so-called hard core bosons regime. > Character of soliton excitations is dramatically different from the usual Gross-Pitaevskii regime. - Abstract: We investigate theoretically soliton excitations and dynamics of their formation in strongly correlated systems of ultracold bosonic atoms in two and three dimensional optical lattices. We derive equations of nonlinear hydrodynamics in the regime of strong interactions and incommensurate fillings, when atoms can be treated as hard core bosons. When parameters change in one direction only we obtain Korteweg-de Vries type equation away from half-filling and modified KdV equation at half-filling. We apply this general analysis to a problem of the decay of the density step. We consider stability of one dimensional solutions to transverse fluctuations. Our results are also relevant for understanding nonequilibrium dynamics of lattice spin models.
Real-time multi-mode neutron multiplicity counter
Rowland, Mark S; Alvarez, Raymond A
2013-02-26
Embodiments are directed to a digital data acquisition method that collects data regarding nuclear fission at high rates and performs real-time preprocessing of large volumes of data into directly useable forms for use in a system that performs non-destructive assaying of nuclear material and assemblies for mass and multiplication of special nuclear material (SNM). Pulses from a multi-detector array are fed in parallel to individual inputs that are tied to individual bits in a digital word. Data is collected by loading a word at the individual bit level in parallel, to reduce the latency associated with current shift-register systems. The word is read at regular intervals, all bits simultaneously, with no manipulation. The word is passed to a number of storage locations for subsequent processing, thereby removing the front-end problem of pulse pileup. The word is used simultaneously in several internal processing schemes that assemble the data in a number of more directly useable forms. The detector includes a multi-mode counter that executes a number of different count algorithms in parallel to determine different attributes of the count data.
Quantum and classical behavior in interacting bosonic systems
Hertzberg, Mark P.
2016-11-21
It is understood that in free bosonic theories, the classical field theory accurately describes the full quantum theory when the occupancy numbers of systems are very large. However, the situation is less understood in interacting theories, especially on time scales longer than the dynamical relaxation time. Recently there have been claims that the quantum theory deviates spectacularly from the classical theory on this time scale, even if the occupancy numbers are extremely large. Furthermore, it is claimed that the quantum theory quickly thermalizes while the classical theory does not. The evidence for these claims comes from noticing a spectacular difference in the time evolution of expectation values of quantum operators compared to the classical micro-state evolution. If true, this would have dramatic consequences for many important phenomena, including laboratory studies of interacting BECs, dark matter axions, preheating after inflation, etc. In this work we critically examine these claims. We show that in fact the classical theory can describe the quantum behavior in the high occupancy regime, even when interactions are large. The connection is that the expectation values of quantum operators in a single quantum micro-state are approximated by a corresponding classical ensemble average over many classical micro-states. Furthermore, by the ergodic theorem, a classical ensemble average of local fields with statistical translation invariance is the spatial average of a single micro-state. So the correlation functions of the quantum and classical field theories of a single micro-state approximately agree at high occupancy, even in interacting systems. Furthermore, both quantum and classical field theories can thermalize, when appropriate coarse graining is introduced, with the classical case requiring a cutoff on low occupancy UV modes. We discuss applications of our results.
Quantum and classical behavior in interacting bosonic systems
NASA Astrophysics Data System (ADS)
Hertzberg, Mark P.
2016-11-01
It is understood that in free bosonic theories, the classical field theory accurately describes the full quantum theory when the occupancy numbers of systems are very large. However, the situation is less understood in interacting theories, especially on time scales longer than the dynamical relaxation time. Recently there have been claims that the quantum theory deviates spectacularly from the classical theory on this time scale, even if the occupancy numbers are extremely large. Furthermore, it is claimed that the quantum theory quickly thermalizes while the classical theory does not. The evidence for these claims comes from noticing a spectacular difference in the time evolution of expectation values of quantum operators compared to the classical micro-state evolution. If true, this would have dramatic consequences for many important phenomena, including laboratory studies of interacting BECs, dark matter axions, preheating after inflation, etc. In this work we critically examine these claims. We show that in fact the classical theory can describe the quantum behavior in the high occupancy regime, even when interactions are large. The connection is that the expectation values of quantum operators in a single quantum micro-state are approximated by a corresponding classical ensemble average over many classical micro-states. Furthermore, by the ergodic theorem, a classical ensemble average of local fields with statistical translation invariance is the spatial average of a single micro-state. So the correlation functions of the quantum and classical field theories of a single micro-state approximately agree at high occupancy, even in interacting systems. Furthermore, both quantum and classical field theories can thermalize, when appropriate coarse graining is introduced, with the classical case requiring a cutoff on low occupancy UV modes. We discuss applications of our results.
Resolution limits for imaging through multi-mode fiber.
Mahalati, Reza Nasiri; Gu, Ruo Yu; Kahn, Joseph M
2013-01-28
We experimentally demonstrate endoscopic imaging through a multi-mode fiber (MMF) in which the number of resolvable image features approaches four times the number of spatial modes per polarization propagating in the fiber. In our method, a sequence of random field patterns is input to the fiber, generating a sequence of random intensity patterns at the output, which are used to sample an object. Reflected power values are returned through the fiber and linear optimization is used to reconstruct an image. The factor-of-four resolution enhancement is due to mixing of modes by the squaring inherent in field-to-intensity conversion. The incoherent point-spread function (PSF) at the center of the fiber output plane is an Airy disk equivalent to the coherent PSF of a conventional diffraction-limited imaging system having a numerical aperture twice that of the fiber. All previous methods for imaging through MMF can only resolve a number of features equal to the number of modes. Most of these methods use localized intensity patterns for sampling the object and use local image reconstruction.
Breakdown of universality in few-boson systems
Deltuva, Arnoldas; Lazauskas, Rimantas
2010-07-15
We develop a series of resonant short-range two-boson potentials reproducing the same two-body low-energy observables and apply them in three- and four-body calculations. We demonstrate that the universal behavior predicted by effective field theory may be strongly violated and analyze the conditions for this phenomenon.
The application of tapered multi-mode fiber in laser signal simulation
NASA Astrophysics Data System (ADS)
Yin, Ruiguang; Guo, Hao; Liang, Weiwei; Zhang, Wenpan; Li, Hui
2016-09-01
According to laser signal simulation, the advantage of application of tapered multi-mode fiber on laser pulse signal transmission was analyzed. By optical system simulation, the effect on the coupling efficiency of 1.06μm laser pulse signal of different angle was analyzed. By optical experiment, the coupling efficiency and transmission mode of different incident angle and force condition were confirmed. Combining the application of simulation system, with convex lens, frosted glass and optical integrator on the outlet of fiber, the far-field energy distribution was measured. According the receiving optical system entrance pupil, the effect on the beam quality to the simulation result was analyzed. The results showed that the application of tapered multi-mode fiber on laser pulse signal simulation is feasible, and the equipment has been used in the engineering projects.
Emergent particle-hole symmetry in spinful bosonic quantum Hall systems
NASA Astrophysics Data System (ADS)
Geraedts, S. D.; Repellin, C.; Wang, Chong; Mong, Roger S. K.; Senthil, T.; Regnault, N.
2017-08-01
When a fermionic quantum Hall system is projected into the lowest Landau level, there is an exact particle-hole symmetry between filling fractions ν and 1 -ν . We investigate whether a similar symmetry can emerge in bosonic quantum Hall states, where it would connect states at filling fractions ν and 2 -ν . We begin by showing that the particle-hole conjugate to a composite fermion "Jain state" is another Jain state, obtained by reverse flux attachment. We show how information such as the shift and the edge theory can be obtained for states which are particle-hole conjugates. Using the techniques of exact diagonalization and infinite density matrix renormalization group, we study a system of two-component (i.e., spinful) bosons, interacting via a δ -function potential. We first obtain real-space entanglement spectra for the bosonic integer quantum Hall effect at ν =2 , which plays the role of a filled Landau level for the bosonic system. We then show that at ν =4 /3 the system is described by a Jain state which is the particle-hole conjugate of the Halperin (221) state at ν =2 /3 . We show a similar relationship between nonsinglet states at ν =1 /2 and 3 /2 . We also study the case of ν =1 , providing unambiguous evidence that the ground state is a composite Fermi liquid. Taken together our results demonstrate that there is indeed an emergent particle-hole symmetry in bosonic quantum Hall systems.
NASA Astrophysics Data System (ADS)
Sennett, Noah; Hinderer, Tanja; Steinhoff, Jan; Buonanno, Alessandra; Ossokine, Serguei
2017-07-01
Binary systems containing boson stars—self-gravitating configurations of a complex scalar field—can potentially mimic black holes or neutron stars as gravitational-wave sources. We investigate the extent to which tidal effects in the gravitational-wave signal can be used to discriminate between these standard sources and boson stars. We consider spherically symmetric boson stars within two classes of scalar self-interactions: an effective-field-theoretically motivated quartic potential and a solitonic potential constructed to produce very compact stars. We compute the tidal deformability parameter characterizing the dominant tidal imprint in the gravitational-wave signals for a large span of the parameter space of each boson star model, covering the entire space in the quartic case, and an extensive portion of interest in the solitonic case. We find that the tidal deformability for boson stars with a quartic self-interaction is bounded below by Λmin≈280 and for those with a solitonic interaction by Λmin≈1.3 . We summarize our results as ready-to-use fits for practical applications. Employing a Fisher matrix analysis, we estimate the precision with which Advanced LIGO and third-generation detectors can measure these tidal parameters using the inspiral portion of the signal. We discuss a novel strategy to improve the distinguishability between black holes/neutrons stars and boson stars by combining tidal deformability measurements of each compact object in a binary system, thereby eliminating the scaling ambiguities in each boson star model. Our analysis shows that current-generation detectors can potentially distinguish boson stars with quartic potentials from black holes, as well as from neutron-star binaries if they have either a large total mass or a large (asymmetric) mass ratio. Discriminating solitonic boson stars from black holes using only tidal effects during the inspiral will be difficult with Advanced LIGO, but third-generation detectors should
Norms of quantum Gaussian multi-mode channels
NASA Astrophysics Data System (ADS)
Frank, Rupert L.; Lieb, Elliott H.
2017-06-01
We compute the Sp→Sp norm of a general Gaussian gauge-covariant multi-mode channel for any 1 ≤ p < ∞ , where Sp is a Schatten space. As a consequence, we verify the Gaussian optimizer conjecture and the multiplicativity conjecture in these cases.
Ultrasonic Motors Using Piezoelectric Ceramic Multi-Mode Vibrators
NASA Astrophysics Data System (ADS)
Takano, Takehiro; Tomikawa, Yoshiro; Ogasawara, Toshiharu; Sugawara, Sumio; Konnon, Masashi
1988-01-01
The purpose of this paper is to report development of an ultrasonic motor using piezoelectric ceramic multi-mode vibrators of circular or annular plates, in which degenerate horizontal vibration modes of the same or different form are used. Some constructions of the motor and its experimental characteristics are presented. The ultrasonic motor investigated herein shows special merit in its thin construction.
NASA Astrophysics Data System (ADS)
Liu, Suzhen; Zhang, Yanwei; Zhang, Chuang; Yang, Qingxin
2017-02-01
Lamb waves are widely used in nondestructive testing (NDT) and structural health monitoring (SHM) for its obvious advantages, such as good directionality, longer-range propagation and lower loss etc. However, it is difficult to analysis and to interpret the echo signals because of its multi-modes and dispersion. In this paper, the properties of single-mode Lamb waves which were excited by double EMAT were studied based on the principles of multi-modes and the characteristics of wave structure. Simulation results show that the double transducer excitation structure can stimulate single-mode Lamb waves and eliminate the extra modes, which are produced by modal conversion at ends of the specimen. The single-mode excitation of Lamb waves is beneficial to reduce the difficulty of signal processing and provide reliable information to locate the defect. The researches in this paper can be used as a theoretical basis to design double transducer excitation system.
Creating and manipulating non-Abelian anyons in cold atom systems using auxiliary bosons
NASA Astrophysics Data System (ADS)
Zhang, Yuhe; Sreejith, G. J.; Jain, J. K.
2015-08-01
The possibility of realizing bosonic fractional quantum Hall effect in ultracold atomic systems suggests a new route to producing and manipulating anyons, by introducing auxiliary bosons of a different species that capture quasiholes and thus inherit their nontrivial braiding properties. States with localized quasiholes at any desired locations can be obtained by annihilating the auxiliary bosons at those locations. We explore how this method can be used to generate non-Abelian quasiholes of the Moore-Read Pfaffian state for bosons at filling factor ν =1 . We show that a Hamiltonian with an appropriate three-body interaction can produce two-quasihole states in two distinct fusion channels of the topological "qubit." Characteristics of these states that are related to the non-Abelian nature can be probed and verified by a measurement of the effective relative angular momentum of the auxiliary bosons, which is directly related to their pair distribution function. Moore-Read states of more than two quasiholes can also be produced in a similar fashion. We investigate some issues related to the experimental feasibility of this approach, in particular, how large the systems should be for a realization of this physics and to what extent this physics carries over to systems with the more standard two-body contact interaction.
Multi-mode Intravascular RF Coil for MRI-guided Interventions
Kurpad, Krishna N.; Unal, Orhan
2011-01-01
Purpose To demonstrate the feasibility of using a single intravascular RF probe connected to the external MRI system via a single coaxial cable to perform active tip tracking and catheter visualization, and high SNR intravascular imaging. Materials and Methods A multi-mode intravascular RF coil was constructed on a 6F balloon catheter and interfaced to a 1.5T MRI scanner via a decoupling circuit. Bench measurements of coil impedances were followed by imaging experiments in saline and phantoms. Results The multi-mode coil behaves as an inductively-coupled transmit coil. Forward looking capability of 6mm is measured. Greater than 3-fold increase in SNR compared to conventional imaging using optimized external coil is demonstrated. Simultaneous active tip tracking and catheter visualization is demonstrated. Conclusions It is feasible to perform 1) active tip tracking, 2) catheter visualization, and 3) high SNR imaging using a single multi-mode intravascular RF coil that is connected to the external system via a single coaxial cable. PMID:21448969
Multi-mode radio frequency device
Gilbert, Ronald W.; Carrender, Curtis Lee; Anderson, Gordon A.; Steele, Kerry D.
2007-02-13
A transponder device having multiple modes of operation, such as an active mode and a passive mode, wherein the modes of operation are selected in response to the strength of a received radio frequency signal. A communication system is also provided having a transceiver configured to transmit a radio frequency signal and to receive a responsive signal, and a transponder configured to operate in a plurality of modes and to activate modes of operation in response to the radio frequency signal. Ideally, each mode of operation is activated and deactivated independent of the other modes, although two or more modes may be concurrently operational.
Unconventional quantum critical points in systems of strongly interacting bosons
NASA Astrophysics Data System (ADS)
Zaleski, T. A.; Kopeć, T. K.
2014-09-01
Using the combined Bogoliubov method and the quantum rotor approach, we map the Bose-Hubbard Hamiltonian of strongly interacting bosons onto U(1) phase action. By unraveling consequences of the nontrivial topology of the U(1) gauge group and the associated ground state degeneracy we found a close kinship of the zero-temperature divergence of the compressibility and the topological susceptibility at degeneracy points, which marks a novel quantum criticality governed by topological features rather than the Landau principle of the symmetry breaking. We argue that the existence of this new type of the criticality may be instrumental in explaining unconventional quantum critical points observed in superconducting cuprates.
Optical characterisation and analysis of multi-mode pixels for use in future far infrared telescopes
NASA Astrophysics Data System (ADS)
McCarthy, Darragh; Trappe, Neil; Murphy, J. Anthony; Doherty, Stephen; Gradziel, Marcin; O'Sullivan, Créidhe; Audley, Michael D.; de Lange, Gert; van der Vorst, Maarten
2016-07-01
In this paper we present the development and verification of feed horn simulation code based on the mode- matching technique to simulate the electromagnetic performance of waveguide based structures of rectangular cross-section. This code is required to model multi-mode pyramidal horns which may be required for future far infrared (far IR) space missions where wavelengths in the range of 30 to 200 µm will be analysed. Multi-mode pyramidal horns can be used effectively to couple radiation to sensitive superconducting devices like Kinetic Inductance Detectors (KIDs) or Transition Edge Sensor (TES) detectors. These detectors could be placed in integrating cavities (to further increase the efficiency) with an absorbing layer used to couple to the radiation. The developed code is capable of modelling each of these elements, and so will allow full optical characterisation of such pixels and allow an optical efficiency to be calculated effectively. As the signals being measured at these short wavelengths are at an extremely low level, the throughput of the system must be maximised and so multi-mode systems are proposed. To this end, the focal planes of future far IR missions may consist of an array of multi-mode rectangular feed horns feeding an array of, for example, TES devices contained in individual integrating cavities. Such TES arrays have been fabricated by SRON Groningen and are currently undergoing comprehensive optical, electrical and thermal verification. In order to fully understand and validate the optical performance of the receiver system, it is necessary to develop comprehensive and robust optical models in parallel. We outline the development and verification of this optical modelling software by means of applying it to a representative multi-mode system operating at 150 GHz in order to obtain sufficiently short execution times so as to comprehensively test the code. SAFARI (SPICA FAR infrared Instrument) is a far infrared imaging grating spectrometer
Ramakrishnan, Raghunathan; Rauhut, Guntram
2015-04-21
Semi-quartic force fields (QFF) rely on a Taylor-expansion of the multi-dimensional Born-Oppenheimer potential energy surface (PES) and are frequently used within the calculation of anharmonic vibrational frequencies based on 2nd order vibrational perturbation theory (VPT2). As such they are usually determined by differentiation of the electronic energy with respect to the nuclear coordinates. Alternatively, potential energy surfaces can be expanded in terms of multi-mode expansions, which typically do not require any derivative techniques. The computational effort to retrieve QFF from size-reduced multi-mode expansions has been studied and has been compared with standard Taylor-expansions. As multi-mode expansions allow for the convenient introduction of subtle approximations, these will be discussed in some detail. In addition, a preliminary study about the applicability of a generalized Duschinsky transformation to QFFs is provided. This transformation allows for the efficient evaluation of VPT2 frequencies of isotopologues from the PES of the parent compound and thus avoids the recalculation of PESs in different axes systems.
Multi-mode passive piezoelectric shunt damping by means of matrix inequalities
NASA Astrophysics Data System (ADS)
Berardengo, M.; Manzoni, S.; Conti, A. M.
2017-09-01
This paper deals with the use of matrix inequalities for the aim of multi-modal piezoelectric shunt damping. The paper shows that the shunt impedance can be seen as a controller in a state space model of the electro-mechanical system; this makes it possible to use the mentioned approach to find the layout of the impedance for different kinds of control problems. The particular focus is on passive multi-mode vibration control with the aim of finding the optimal shunt impedance among the passive and realizable candidates. The proposed method overcomes most of the problems related to the development of the optimal shunt electrical network, which arise when using the most common shunt design strategies for multi-mode control. The results were validated experimentally and compared to well-established methods for multi-mode shunt damping. The proposed method proved to be effective, and the results demonstrate the capability of the matrix inequality approach to provide attenuation levels that are usually higher than those from the reference methods.
The Semi-Infinite q-Boson System with Boundary Interaction
NASA Astrophysics Data System (ADS)
van Diejen, Jan Felipe; Emsiz, Erdal
2014-01-01
Upon introducing a one-parameter quadratic deformation of the q-boson algebra and a diagonal perturbation at the end point, we arrive at a semi-infinite q-boson system with a two-parameter boundary interaction. The eigenfunctions are shown to be given by Macdonald's hyperoctahedral Hall-Littlewood functions of type BC. It follows that the n-particle spectrum is bounded and absolutely continuous and that the corresponding scattering matrix factorizes as a product of two-particle bulk and one-particle boundary scattering matrices.
A biconical taper multi-mode fiber SERS sensor
NASA Astrophysics Data System (ADS)
Bai, Hua; Chen, Zhenyi; Chen, Na; Guo, Qiang; Zhang, Kun; Pang, Fufei; Wang, Tingyun
2010-12-01
A surface-enhanced Raman scattering (SERS) optical fiber sensor using biconical taper multi-mode fiber (MMF) is proposed. It is fabricated by fused elongating a multi-mode fiber and then coated the silver colloid on its waist. The main advantage of this sensor is that it can increase the SERS active substrate region to make more molecules be excited to produce Raman signal. Silver colloid is selected as the active substrate of SERS. A modified immobilizing process is introduced to increase the thickness of the immobilized layer and reduce the preparation time. Various concentration of R6G is used to detect the performance of the sensor. Strong Raman signal is detected from the waist of the tapered fiber. The detection sensitivity is up to 10-9M.
Perturbative Approaching for Boson Fields' System in a Lewis-Papapetrou Space-Time
Murariu, G.; Dariescu, M. A.; Dariescu, C.
2010-08-04
In this paper the first order solutions of a Klein--Gordon--Maxwell--Einstein coupled system equations were derived for boson fields in a Lewis Papapetrou space time. The results expand the previous static solutions obtained in literature. A main goal is represented by the symbolic script built for such approach.
Quantum Integrals for a Semi-Infinite q-Boson System with Boundary Interactions
NASA Astrophysics Data System (ADS)
van Diejen, Jan Felipe; Emsiz, Erdal
2015-05-01
We provide explicit formulas for the quantum integrals of a semi-infinite q-boson system with boundary interactions. These operators and their commutativity are deduced from the Pieri formulas for a qto 0 Hall-Littlewood type degeneration of the Macdonald-Koornwinder polynomials.
Huang, Songling; Zhang, Yu; Wang, Shen; Zhao, Wei
2016-05-02
This paper proposes a new cross-hole tomography imaging (CTI) method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs). The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically studied. The principles and procedures for the cooperation of A0- and S0-mode LW CTI are proposed. Moreover, the experimental LW imaging system on an aluminum plate with a variable-depth defect is set up, based on A0- and S0-mode EMAT (electromagnetic acoustic transducer) arrays. For comparison, the traditional single-mode LW CTI method is used in the same experimental platform. The imaging results show that the computed thickness distribution by the proposed multi-mode method more accurately reflects the actual thickness variation of the defect, while neither the S0 nor the A0 single-mode method was able to distinguish thickness variation in the defect region. Moreover, the quantification of the defect's thickness variation is more accurate with the multi-mode method. Therefore, theoretical and practical results prove that the variable-depth defect in metal plates can be successfully quantified and visualized by the proposed multi-mode electromagnetic ultrasonic LW CTI method.
Huang, Songling; Zhang, Yu; Wang, Shen; Zhao, Wei
2016-01-01
This paper proposes a new cross-hole tomography imaging (CTI) method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs). The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically studied. The principles and procedures for the cooperation of A0- and S0-mode LW CTI are proposed. Moreover, the experimental LW imaging system on an aluminum plate with a variable-depth defect is set up, based on A0- and S0-mode EMAT (electromagnetic acoustic transducer) arrays. For comparison, the traditional single-mode LW CTI method is used in the same experimental platform. The imaging results show that the computed thickness distribution by the proposed multi-mode method more accurately reflects the actual thickness variation of the defect, while neither the S0 nor the A0 single-mode method was able to distinguish thickness variation in the defect region. Moreover, the quantification of the defect’s thickness variation is more accurate with the multi-mode method. Therefore, theoretical and practical results prove that the variable-depth defect in metal plates can be successfully quantified and visualized by the proposed multi-mode electromagnetic ultrasonic LW CTI method. PMID:27144571
Energy enhancements in mode-locked laser cavities using multi-mode fiber lasers
NASA Astrophysics Data System (ADS)
Ding, Edwin; Kutz, J. Nathan
2010-02-01
The averaged mode-locking dynamics in a multi-mode fiber is studied. The transverse mode structures of the electric field are determined from a linear eigenvalue problem, and the co-propagation of the corresponding mode envelopes is governed by a system of coupled Ginzburg-Landau equations (CGLEs) which accounts explicitly for bandwidth-limited saturable gain as well as saturable absorption. Simulations show that stable and robust modelocked pulses with high energy can be produced. The maximum pulse energy is simulated as a function of the linear coupling and coiling loss. The present work provides for an excellent tool for characterizing mode-locking performance.
Direct measurements of entanglement entropy in one-dimensional bosonic systems
NASA Astrophysics Data System (ADS)
Lukin, Alexander; Tai, Eric; Ma, Ruichao; Preiss, Philipp; Rispoli, Matthew; Islam, Rajibul; Greiner, Markus
2015-05-01
The presence of large-scale entanglement is a defining characteristic of exotic quantum phases of matter. However, its experimental verification is an outstanding challenge in condensed matter physics. Within small quantum information processing units, entanglement may be detected via resource-intensive state tomography or class-specific entanglement witnesses. Here, we demonstrate a novel approach to the measurement of entanglement entropy of any bosonic system, using a quantum gas microscope with tailored potential landscapes. We extend the concept of Hong-Ou-Mandel interference from two particles to many-body states. Interfering two copies of identically prepared states measures the quantum mechanical purity of the system and its subsystems, placing bounds on the entanglement entropy. We apply this technique to observe the entanglement dynamics in a few-particle quench of a bosonic system. Our protocol may be applied to any many-body state and provides a new platform for the characterization of strongly correlated states in optical lattices.
Open Systems with Error Bounds: Spin-Boson Model with Spectral Density Variations
NASA Astrophysics Data System (ADS)
Mascherpa, F.; Smirne, A.; Huelga, S. F.; Plenio, M. B.
2017-03-01
In the study of open quantum systems, one of the most common ways to describe environmental effects on the reduced dynamics is through the spectral density. However, in many models this object cannot be computed from first principles and needs to be inferred on phenomenological grounds or fitted to experimental data. Consequently, some uncertainty regarding its form and parameters is unavoidable; this in turn calls into question the accuracy of any theoretical predictions based on a given spectral density. Here, we focus on the spin-boson model as a prototypical open quantum system, find two error bounds on predicted expectation values in terms of the spectral density variation considered, and state a sufficient condition for the strongest one to apply. We further demonstrate an application of our result, by bounding the error brought about by the approximations involved in the hierarchical equations of motion resolution method for spin-boson dynamics.
Open Systems with Error Bounds: Spin-Boson Model with Spectral Density Variations.
Mascherpa, F; Smirne, A; Huelga, S F; Plenio, M B
2017-03-10
In the study of open quantum systems, one of the most common ways to describe environmental effects on the reduced dynamics is through the spectral density. However, in many models this object cannot be computed from first principles and needs to be inferred on phenomenological grounds or fitted to experimental data. Consequently, some uncertainty regarding its form and parameters is unavoidable; this in turn calls into question the accuracy of any theoretical predictions based on a given spectral density. Here, we focus on the spin-boson model as a prototypical open quantum system, find two error bounds on predicted expectation values in terms of the spectral density variation considered, and state a sufficient condition for the strongest one to apply. We further demonstrate an application of our result, by bounding the error brought about by the approximations involved in the hierarchical equations of motion resolution method for spin-boson dynamics.
Bosonization theory for tunneling spectra in smooth edges of quantum Hall systems
NASA Astrophysics Data System (ADS)
Conti, Sergio; Vignale, Giovanni
1998-01-01
We calculate the spectral function of a smooth edge of a quantum Hall system in the lowest Landau level by means of a bosonization technique. We obtain a general relationship between the one electron spectral function and the dynamical structure factor. The resulting I-V characteristics exhibit, at low voltage and temperature, power law scaling, generally different from the one predicted by the chiral Luttinger liquid theory, and in good agreement with recent experimental results.
Hirokawa, Masao )
1993-04-01
The authors clarify the mathematical difficulty when for bosonic systems (i.e., unbounded operators) they rigorously construct a Liouville space, in which a Liouville operator acts, associated with a Hamiltonian, including unbounded and non-quasi-free cases. Thermo field dynamics are given as an expression equivalent to the Liouville space and operator. The authors investigate the mathematical properties of them, and thus clarify the mathematical properties of the thermal state. 32 refs.
NASA Astrophysics Data System (ADS)
Lee, Changgil; Park, Seunghee
2011-11-01
In a structure, several types of damage can occur, ranging from micro-cracking to corrosion or loose bolts. This makes identifying the damage difficult with a single mode of sensing. Therefore, a multi-mode actuated sensing system is proposed based on a self-sensing circuit using a piezoelectric sensor. In self-sensing-based multi-mode actuated sensing, one mode provides a wide frequency-band structural response from the self-sensed impedance measurement and the other mode provides a specific frequency-induced structural wavelet response from the self-sensed guided wave measurement. In this experimental study, a pipeline system under water flow operation was examined to verify the effectiveness and robustness of the proposed structural health monitoring approach. Different types of structural damage were inflicted artificially on the pipeline system. To classify the multiple types of structural damage, supervised learning-based statistical pattern recognition was implemented by composing a three-dimensional space using the damage indices extracted from the impedance and guided wave features as well as temperature variations. For a more systematic damage classification, several control parameters were optimized to determine an optimal decision boundary for the supervised learning-based pattern recognition. Further research issues are also discussed for real-world implementations of the proposed approach.
TeraSCREEN: multi-frequency multi-mode Terahertz screening for border checks
NASA Astrophysics Data System (ADS)
Alexander, Naomi E.; Alderman, Byron; Allona, Fernando; Frijlink, Peter; Gonzalo, Ramón; Hägelen, Manfred; Ibáñez, Asier; Krozer, Viktor; Langford, Marian L.; Limiti, Ernesto; Platt, Duncan; Schikora, Marek; Wang, Hui; Weber, Marc Andree
2014-06-01
The challenge for any security screening system is to identify potentially harmful objects such as weapons and explosives concealed under clothing. Classical border and security checkpoints are no longer capable of fulfilling the demands of today's ever growing security requirements, especially with respect to the high throughput generally required which entails a high detection rate of threat material and a low false alarm rate. TeraSCREEN proposes to develop an innovative concept of multi-frequency multi-mode Terahertz and millimeter-wave detection with new automatic detection and classification functionalities. The system developed will demonstrate, at a live control point, the safe automatic detection and classification of objects concealed under clothing, whilst respecting privacy and increasing current throughput rates. This innovative screening system will combine multi-frequency, multi-mode images taken by passive and active subsystems which will scan the subjects and obtain complementary spatial and spectral information, thus allowing for automatic threat recognition. The TeraSCREEN project, which will run from 2013 to 2016, has received funding from the European Union's Seventh Framework Programme under the Security Call. This paper will describe the project objectives and approach.
Photonic lattice simulation of dissipation-induced correlations in bosonic systems
Rai, Amit; Lee, Changhyoup; Noh, Changsuk; Angelakis, Dimitris G.
2015-01-01
We propose an optical simulation of dissipation-induced correlations in one-dimensional (1D) interacting bosonic systems, using a two-dimensional (2D) array of linear photonic waveguides and only classical light. We show that for the case of two bosons in a 1D lattice, one can simulate on-site two-body dissipative dynamics using a linear 2D waveguide array with lossy diagonal waveguides. The intensity distribution of the propagating light directly maps out the wave function, allowing one to observe the dissipation-induced correlations with simple measurements. Beyond the on-site model, we also show that a generalised model containing nearest-neighbour dissipative interaction can be engineered and probed in the proposed set-up. PMID:25708778
General variational many-body theory with complete self-consistency for trapped bosonic systems
Streltsov, Alexej I.; Alon, Ofir E.; Cederbaum, Lorenz S.
2006-06-15
In this work we develop a complete variational many-body theory for a system of N trapped bosons interacting via a general two-body potential. The many-body solution of this system is expanded over orthogonal many-body basis functions (configurations). In this theory both the many-body basis functions and the respective expansion coefficients are treated as variational parameters. The optimal variational parameters are obtained self-consistently by solving a coupled system of noneigenvalue--generally integro-differential--equations to get the one-particle functions and by diagonalizing the secular matrix problem to find the expansion coefficients. We call this theory multiconfigurational Hartree theory for bosons or MCHB(M), where M specifies explicitly the number of one-particle functions used to construct the configurations. General rules for evaluating the matrix elements of one- and two-particle operators are derived and applied to construct the secular Hamiltonian matrix. We discuss properties of the derived equations. We show that in the limiting cases of one configuration the theory boils down to the well-known Gross-Pitaevskii and the recently developed multi-orbital mean fields. The invariance of the complete solution with respect to unitary transformations of the one-particle functions is utilized to find the solution with the minimal number of contributing configurations. In the second part of our work we implement and apply the developed theory. It is demonstrated that for any practical computation where the configurational space is restricted, the description of trapped bosonic systems strongly depends on the choice of the many-body basis set used, i.e., self-consistency is of great relevance. As illustrative examples we consider bosonic systems trapped in one- and two-dimensional symmetric and asymmetric double well potentials. We demonstrate that self-consistency has great impact on the predicted physical properties of the ground and excited states
Multi-mode clustering model for hierarchical wireless sensor networks
NASA Astrophysics Data System (ADS)
Hu, Xiangdong; Li, Yongfu; Xu, Huifen
2017-03-01
The topology management, i.e., clusters maintenance, of wireless sensor networks (WSNs) is still a challenge due to its numerous nodes, diverse application scenarios and limited resources as well as complex dynamics. To address this issue, a multi-mode clustering model (M2 CM) is proposed to maintain the clusters for hierarchical WSNs in this study. In particular, unlike the traditional time-trigger model based on the whole-network and periodic style, the M2 CM is proposed based on the local and event-trigger operations. In addition, an adaptive local maintenance algorithm is designed for the broken clusters in the WSNs using the spatial-temporal demand changes accordingly. Numerical experiments are performed using the NS2 network simulation platform. Results validate the effectiveness of the proposed model with respect to the network maintenance costs, node energy consumption and transmitted data as well as the network lifetime.
Bose-Einstein Condensation in a One-Dimensional System of Interacting Bosons
NASA Astrophysics Data System (ADS)
Tomchenko, Maksim
2016-03-01
Using the Vakarchuk formulae for the density matrix, we calculate the number Nk of atoms with momentum hbar k for the ground state of a uniform one-dimensional periodic system of interacting bosons. We obtain for impenetrable point bosons N0 ≈ 2√{N} and N_{k=2π j/L} ˜eq 0.31 N0/√{|j|}. That is, there is no condensate or quasicondensate on low levels at large N. For almost point bosons with weak coupling (β =ν 0m/π ^{2hbar 2n} ≪ 1), we obtain N0/N ≈ ( 2/N√{β }) ^{&sqrt{β; }/2} and N_{k=2π j/L} ≈ N0√{β }/4|j|^{1-√{β /2}}. In this case, the quasicondensate exists on the level with k=0 and on low levels with kne 0, if N is large and β is small (e.g., for N ˜ 10^{10} , β ˜ 0.01). A method of measurement of such fragmented quasicondensate is proposed.
Thermodynamics of boson systems related to Dunkl differential-difference operators
NASA Astrophysics Data System (ADS)
Ubriaco, Marcelo R.
2014-11-01
We study the thermodynamics of systems based on a Fock space representation inspired by the differential-difference operators proposed in Dunkl (1989). We calculate thermodynamic functions as the entropy and heat capacity and compare them with the standard boson case. A calculation of the second virial coefficient and the scalar curvature in two and three dimensions show that these systems become repulsive within an interval of negative values of the reflection operator parameter θ. In addition, the stability of this system is examined as a function of θ.
NASA Astrophysics Data System (ADS)
Bâldea, Ioan; Franz, Jan; Szalay, Péter G.; Köppel, Horst
2006-10-01
The multi-mode vibronic interactions between the five lowest electronic states of the fluorobenzene radical cation are investigated theoretically, based on ab initio electronic structure data, and employing the linear vibronic coupling model. Low-energy conical intersections, and strong vibronic couplings are found to prevail within the set of X˜-A˜ and B˜-C˜-D˜ cationic states, while the interactions between these two sets of states are found to be rather weak (owing to high-energy conical intersections). The overall intensity distribution of the experimental photoelectron spectrum, as well as the line positions observed in the MATI spectrum, are well reproduced. The vibronic interactions in the X˜-A˜ states are found to be a replica of the multi-mode dynamical Jahn-Teller effect in the parent system, the XE ground state of the benzene radical cation. Ultrafast internal conversion processes within the electronic manifolds in question demonstrate the strength of the nonadiabatic coupling effects and complement the analogous findings for the electronic spectra. The implications for the fluorescence dynamics of the fluorobenzene radical cation are discussed.
Quantum law of rare events for systems with bosonic symmetry.
Sokolovski, D
2013-03-15
In classical physics, the joint probability of a number of individually rare independent events is given by the Poisson distribution. It describes, for example, the unidirectional transfer of a population between the densely and sparsely populated states of a classical two-state system. We derive a quantum version of the law for a large number of noninteracting systems (particles) obeying Bose-Einstein statistics. The classical law is significantly modified by quantum interference, which allows, among other effects, for the counterflow of particles back into the densely populated state. The suggested observation of this classically forbidden counterflow effect can be achieved with modern laser-based techniques used for manipulating and trapping cold atoms.
Duration of classicality in highly degenerate interacting Bosonic system
NASA Astrophysics Data System (ADS)
Todarello, Elisa; Sikivie, Pierre
2017-01-01
We study sets of oscillators that have high quantum occupancy and that interact by exchanging quanta. It is shown by analytical arguments and numerical simulations that such systems obey classical equations of motion only on timescales of order their relaxation time τ and not longer than that. The results are relevant to the cosmology of axions and axion-like particles. U. S. Department of Energy.
Generation and entanglement of multi-dimensional multi-mode coherent fields in cavity QED
NASA Astrophysics Data System (ADS)
Maleki, Y.
2016-11-01
We introduce generalized multi-mode superposition of multi-dimensional coherent field states and propose a generation scheme of such states in a cavity QED scenario. An appropriate encoding of information on these states is employed, which maps the states to the Hilbert space of some multi-qudit states. The entanglement of these states is characterized based on such proper encodings. A detailed study of entanglement in general multi-qudit coherent states is presented, and in addition to establishing some explicit expressions for quantifying entanglement of such systems, several important features of entanglement in these system states are exposed. Furthermore, the effects of both cavity decay and channel noise on these system states are studied and their properties are illustrated.
Retarded boson-fermion interaction in atomic systems
NASA Astrophysics Data System (ADS)
Datta, Sambhu N.; Misra, Anirban
2006-08-01
The retarded interaction between an electron and a spin-0 nucleus is derived from electrodynamical perturbation theory. The contribution of retardation at order v2/c2 mimics the Breit interaction [Phys. Rev. 34, 553 (1929); 36, 388 (1930); 39, 616 (1932)] with the Dirac matrix α2 being replaced by p2/m2c where p2 is the linear momentum operator for the nucleus. An effective one-electron retardation operator is obtained in relative coordinates, and this can be used through all orders in perturbation theory without any problem of infinite degeneracy. A few steps of unitary transformation lead to the nonrelativistic limit. The leading terms in retardation corrections to energy are of order (me/mn)α2Z4(α2mec2). The implications for atomic systems are discussed.
Long, Feng; Zhu, Anna; Shi, Hanchang
2014-03-21
We demonstrate an integrated fiber optic photoluminescence sensing platform using a novel single-multi-mode fiber coupler (SMFC)-based probe with high collection efficiency for fluorescence signals. The SMFC, prepared using fused biconical taper technology, not only transmits excitation light, but also collects and transmits fluorescence. The entire system does not use complex optical components and rarely requires optical alignment. The simple structure of the SMFC considerably improves the light transmission efficiency, signal-to-noise ratio, and sensitivity of the system. Theoretical and experimental results show that the proposed probe increases the collection efficiency by more than eight-fold compared with a bifurcated fiber probe. The performance of the proposed probe was experimentally evaluated by measuring the fluorescence spectra of well-known targets and a fresh Tall Fescue leaf.
Ultra-Wideband Massive MIMO Communications Using Multi-mode Antennas
NASA Astrophysics Data System (ADS)
Hoeher, P. A.; Manteuffel, D.; Doose, N.; Peitzmeier, N.
2017-08-01
An ultra-wideband system design is presented which supports wireless internet access and similar short-range applications with data rates of the order of 100 Gbps. Unlike concurrent work exploring the 60 GHz regime and beyond for this purpose, our focus is on the 6.0 -8.5 GHz frequency band. Hence, a bandwidth efficiency of about 50 bps/Hz is necessary. This sophisticated goal is targeted by employing two key enabling techniques: massive MIMO communications in conjunction with multi-mode antennas. This concept is suitable both for small-scale terminals like smartphones, as well as for powerful access points. Compared to millimeter wave and THz band communications, the 6.0 -8.5 GHz frequency band offers more robustness in NLOS scenarios and is more mature with respect to system components.
[Study on CO2 measurement using tunable multi-mode diode laser absorption spectroscopy].
Gao, Guang-Zhen; Chen, Bao-Xue; Hu, Bo; Long, Xiu-Hui; Li, Ai-Ping; Li, Rong
2013-12-01
Tunable diode laser absorption spectroscopy (TDLAS) technology is a kind of fast time response, large-range, continuous on-line monitoring gas detection technique. It is the mainstream technology of gas detection. In this paper the multimode laser diode was used as light source. Multi-mode laser combined with correlation spectroscopy can improve the test reliability and stability. It can also conquer the problem of the central wavelength change of the single mode diode laser due to thermal or mechanical fluctuations in durable working process. A FP laser was used as the light source in this research. A multi-mode diode laser system based on correlation spectroscopy and wavelength modulation spectroscopy (TMDL-COSPEC-WMS) was used to measure carbon dioxide in ambient air around 1 570 nm. The carbon dioxide concentrations were derived from the relationship between the normalized WMS-2f signal peak heights of the measurement and reference signals which selected based on high signal to noise ratio and correlation coefficient. All measurements were performed with controlled carbon dioxide and nitrogen mixtures in which carbon dioxide concentrations range from 0. 6% to 30%. The calculation results showed that there was a high linear relationship between the measured and actual carbon dioxide concentration, the linearity was 0. 998 7 and the fitted slope was 1. 061+/-0. 016 8 respectively over the tested range. A detection limit of 335 ppm m was achieved. The standard deviation of 0. 036 7% was achieved using 20 successive measurements with each measurement time taking approximately 10 s during 20 minutes, which demonstrated good stability of the system. Good agreements between the measurements of the system and actual values confirm the accuracy and potential utility of the system for carbon dioxide detection.
Physics basis of Multi-Mode anomalous transport module
Rafiq, T.; Kritz, A. H.; Luo, L.; Weiland, J.; Pankin, A. Y.
2013-03-15
The derivation of Multi-Mode anomalous transport module version 8.1 (MMM8.1) is presented. The MMM8.1 module is advanced, relative to MMM7.1, by the inclusion of peeling modes, dependence of turbulence correlation length on flow shear, electromagnetic effects in the toroidal momentum diffusivity, and the option to compute poloidal momentum diffusivity. The MMM8.1 model includes a model for ion temperature gradient, trapped electron, kinetic ballooning, peeling, collisionless and collision dominated magnetohydrodynamics modes as well as model for electron temperature gradient modes, and a model for drift resistive inertial ballooning modes. In the derivation of the MMM8.1 module, effects of collisions, fast ion and impurity dilution, non-circular flux surfaces, finite beta, and Shafranov shift are included. The MMM8.1 is used to compute thermal, particle, toroidal, and poloidal angular momentum transports. The fluid approach which underlies the derivation of MMM8.1 is expected to reliably predict, on an energy transport time scale, the evolution of temperature, density, and momentum profiles in plasma discharges for a wide range of plasma conditions.
NASA Astrophysics Data System (ADS)
Ahrens, Andreas; Sandmann, Andre; Bremer, Kort; Roth, Bernhard; Lochmann, Steffen
2015-09-01
In this paper multiple-input multiple-output (MIMO) signal processing is investigated for fibre optic sensor applications. A (2 × 2) MIMO implementation is realized by using lower-order and higher-order mode groups of a graded-index (GI) multi-mode fibre (MMF) as separate transmission channels. A micro-bending pressure sensor changes these separate transmission characteristics and introduces additional crosstalk. By observing the weight-factors of the MIMO system the amount of load applied was determined. Experiments verified a good correlation between the change of the MIMO weight coefficients and the load applied to the sensor and thus verified that MIMO signal processing can beneficially be used for fibre optic sensor applications.
Splice loss requirements in multi-mode fiber mode-division-multiplex transmission links.
Warm, Stefan; Petermann, Klaus
2013-01-14
We investigate numerically the influence of fiber splices and fiber connectors to the statistics of mode dependent loss (MDL) and multiple-input multiple-output (MIMO) outage capacity in mode multiplexed multi-mode fiber links. Our results indicate required splice losses much lower than currently feasible to achieve a reasonable outage capacity in long-haul transmission systems. Splice losses as low as 0.03dB may effectively lead to an outage of MIMO channels after only a few hundred kilometers transmission length. In a first approximation, the relative capacity solely depends on the accumulated splice loss and should be less than ≈ 2dB to ensure a relative capacity of 90%. We also show that discrete mode permutation (mixing) within the transmission line may effectively increase the maximum transmission distance by a factor of 5 for conventional splice losses.
EMTP modeling of electromagnetic transients in multi-mode coaxial cables by finite sections
Meredith, R.J.
1997-01-01
This paper introduces a way of modeling electromagnetic propagation in conductive materials, termed the method of finite sections. It addresses the issues of modeling frequency-dependent impedances and frequency-dependent coupling of conductors. Its use is demonstrated by application to transient modeling of a multi-mode coaxial cable system in the Electromagnetic Transients Program (EMTP), a situation which currently eludes accurate representation. In addition to its use in modeling coaxial cables, the method is applicable to modeling of overhead lines, pipe-type cables, transformer cores and walls, lightning arrestors and other situations in which sufficient planar or cylindrical symmetry exists. The method provides the only accurate EMTP means of modeling wave propagation in non-linear resistive and/or inductive conductors.
Nonlinear optics of multi-mode planar photonic crystal microcavities
NASA Astrophysics Data System (ADS)
McCutcheon, Murray William
The nonlinear properties of multi-mode InP and Si planar photonic crystal microcavities are investigated in experiments relevant to integrated schemes for classical and quantum optical information processing. Normally incident, short laser pulses are used to coherently initialize the relative phase and amplitudes of two modes of a single-missing-hole InP microcavity. The two modes are orthogonally polarized, and separated by less than the bandwidth of the ˜ 130 fs excitation pulses. The relative amplitudes of the two modes can be controlled by adjusting the polarization and the centre frequency of the excitation beam. Cross-polarized detection of the resonantly scattered light reveals a well-defined relative phase between the modes that is characteristic of their coherence. When the short-pulse excitation is used to coherently excite two modes in a three-hole line-defect (L3) InP microcavity, second-order harmonic radiation is observed due to the interactions of the resonant fields with the second-order nonlinear susceptibility (chi(2)) of the host InP slab. Second-harmonic and sum-frequency generated signals are observed due to the intra- and inter-mode nonlinear mixing of the microcavity fields. When a separate non-resonant pulse is focussed onto an InP microcavity, sum-frequency light is generated conditional to the resonant mode population of the microcavity. The conditionally generated signals can be tuned by tuning the frequency of the non-resonant pulse. All of the results can be explained with reference to the bulk chi(2) properties of the InP slab. While the transient, multi-mode response of the microcavities is harnessed with the short-pulse technique, a continuous wave excitation laser exploits the local-field enhancement intrinsic to these wavelength-scale microcavities. A single-mode InP L3-microcavity with Q = 3,800 is pumped on resonance with a CW laser, and the 2D pattern of far-field second-harmonic radiation is directly imaged. The second
Multi-modes processes for stretched spiral vortex formation
NASA Astrophysics Data System (ADS)
Horiuti, Kiyosi
2004-11-01
We studied a process for formation of the stretched spiral vortex (Lundgren 1982) in incompressible homogeneous isotropic turbulence. It was shown that multi modes exist for the configuration of alignment between the vorticity vectors along the vortex tube core and the vorticity vector along the sheet which emanates from and wraps around the tube core. A representative one is that generated via a roll-up of the vortex sheet through focusing, in which these two vorticity vectors were parallel. Alternative mechanism for formation of this parallel configuration was through the interaction of two different sheets which were initially placed perpendicular to each other. These two sheets generated a weak circulation and it gradually accumulated to form the tube core region. These two sheets were entrained by the tube core and the spiral sheets emanating from the tube core was formed. The tubes in this mode persisted for a rather long period of time. In another mode, the vorticity vectors along the sheet were in the direction transverse to those along the tube core. It was found that this mode often takes an asymmetric configuration in which the vorticity vectors along one of the sheets were parallel to those along the tube, while the vectors along another sheet were transverse to those along the tube. The configuration in which the vorticity vectors along both sheets were transverse to those along the tube core (Pullin and Lundgren 2001) was rarely found. Intense energy cascade took place with the stretching of the spiral vortex sheets. As the Reynolds number was increased, the frequency of occurrence of the spiral vortex formation increased, and the energy spectrum showed a profile close to the -5/3 law.
Simulated Annealing Inversion of Multi-mode Rayleigh Waves
NASA Astrophysics Data System (ADS)
Schmitt, D. R.
2001-12-01
Rayleigh-wave velocity dispersion curves provide important constraints on the shear-wave velocity structure from the surface. Most Rayleigh wave studies assume the propagating surface-wave packet is composed solely of the primary Rayleigh mode. However, in near-surface studies higher order Rayleigh wave modes contain a sizable fraction of the propagating surface wave energy; and interference of the various modes complicates analysis. Inversion of Rayleigh wave dispersion curves for structure is further complicated by the inherent nonlinearity of the problem. Simulated annealing is a popular method for solving such problems but has not before been applied to the inversion of multi-mode Rayleigh wave dispersion curves. We applied this method to a near-surface set of Rayleigh waves produced by hammer blows onto the surface of a thick clay layer and recorded by an array 3-component geophones offset from the source from 7-m to 38-m at a 0.5-m spacing. Three strong Rayleigh wave modes were detected over the frequencies from 10-Hz to 80-Hz from the observed traces using a modified slant-stack method. Inversion of the three resulting dispersion curves provided a stable inversion that agreed well with the geologic stratification known from wellbore measurements and coring. In contrast, use of only the primary Rayleigh-wave dispersion curve provided a solution in poorer agreement with the geology despite matching the dispersion curve well. This study suggests that incorporating higher order Rayleigh wave modes yields a more reliable solution for geologic interpretation of near surface structure.
Interaction-induced persistent-current enhancement in frustrated bosonic systems
NASA Astrophysics Data System (ADS)
Kerala Varma, Vipin; Sánchez, Ramsés J.
2015-07-01
We investigate the effect of next-nearest-neighbor hopping on the zero-temperature Drude weight or superfluidity in mesoscopic one-dimensional systems of (a) a single particle with quasidisorder (Aubry-André model) and (b) hard-core bosons with nearest-neighbor interaction. We show that there is an interaction-induced enhancement of the Drude weight when the next-nearest-neighbor hopping is frustrated for the many-body system. The observed nonmonotonic behavior of the Drude weight occurs because the repulsive interactions first suppress the frustration in the system, leading to a rise in the Drude weight, whereas at much larger interaction strengths the charge density wave fluctuations set in the insulator and the Drude weight drops. The present paper reveals a scenario in which a persistent flow enhancement is plausible in the presence of kinetic frustration and repulsive interactions.
Alonso, C. E.; Arias, J. M.; Vitturi, A.
2007-02-02
We investigate phase transitions in boson-fermion systems. We propose an analytically solvable model [E(5/12)] to describe odd nuclei at the critical point in the transition from the spherical to {gamma}-unstable behavior. In the model, a boson core described within the Bohr Hamiltonian interacts with an unpaired particle assumed to be moving in the three single-particle orbitals j=1/2, 3/2, 5/2. Energy spectra and electromagnetic transitions at the critical point compare well with the results obtained within the interacting boson-fermion model, with a boson-fermion Hamiltonian that describes the same physical situation.
Alonso, C E; Arias, J M; Vitturi, A
2007-02-02
We investigate phase transitions in boson-fermion systems. We propose an analytically solvable model [E(5/12)] to describe odd nuclei at the critical point in the transition from the spherical to gamma-unstable behavior. In the model, a boson core described within the Bohr Hamiltonian interacts with an unpaired particle assumed to be moving in the three single-particle orbitals j=1/2, 3/2, 5/2. Energy spectra and electromagnetic transitions at the critical point compare well with the results obtained within the interacting boson-fermion model, with a boson-fermion Hamiltonian that describes the same physical situation.
NASA Astrophysics Data System (ADS)
Graefe, Eva-Maria; Korsch, Hans Jürgen; Rush, Alexander
2016-04-01
Bosonic quantum conversion systems can be modeled by many-particle single-mode Hamiltonians describing a conversion of m molecules of type A into n molecules of type B and vice versa. These Hamiltonians are analyzed in terms of generators of a polynomially deformed su(2) algebra. In the mean-field limit of large particle numbers, these systems become classical and their Hamiltonian dynamics can again be described by polynomial deformations of a Lie algebra, where quantum commutators are replaced by Poisson brackets. The Casimir operator restricts the motion to Kummer shapes, deformed Bloch spheres with cusp singularities depending on m and n . It is demonstrated that the many-particle eigenvalues can be recovered from the mean-field dynamics using a WKB-type quantization condition. The many-particle state densities can be semiclassically approximated by the time periods of periodic orbits, which show characteristic steps and singularities related to the fixed points, whose bifurcation properties are analyzed.
Correlation versus commensurability effects for finite bosonic systems in one-dimensional lattices
Brouzos, Ioannis; Schmelcher, Peter; Zoellner, Sascha
2010-05-15
We investigate few-boson systems in finite one-dimensional multiwell traps covering the full interaction crossover from uncorrelated to fermionized particles. Our treatment of the ground-state properties is based on the numerically exact multiconfigurational time-dependent Hartree method. For commensurate filling, we trace the fingerprints of localization as the interaction strength increases, in several observables like reduced-density matrices, fluctuations, and momentum distribution. For a filling factor larger than 1 we observe on-site repulsion effects in the densities and fragmentation of particles beyond the validity of the Bose-Hubbard model upon approaching the Tonks-Girardeau limit. The presence of an incommensurate fraction of particles induces incomplete localization and spatial modulations of the density profiles, taking into account the finite size of the system.
NASA Astrophysics Data System (ADS)
Wang, Qun; Gao, Qing-Yu; Lü, Hua-Ping; Zheng, Zhi-Gang
2010-05-01
Multi-mode spiral wave and its breakup in 1-d and 2-d coupled oscillatory media is studied here by theoretic analysis and numerical simulations. The analysis in 1-d system shows that the dispersion relation curve could be non-monotonic depending on the coupling strength. It may also lead to the coexistence of different wave numbers within one system. Direct numerical observations in 1-d and 2-d systems conform to the prediction of dispersion relation analysis. Our findings indicate that the wave grouping can also be observed in oscillatory media without tip meandering and waves with negative group velocity can occur without inhomogeneity.
Multi-mode of Four and Six Wave Parametric Amplified Process
Zhu, Dayu; Yang, Yiheng; Zhang, Da; Liu, Ruizhou; Ma, Danmeng; Li, Changbiao; Zhang, Yanpeng
2017-01-01
Multiple quantum modes in correlated fields are essential for future quantum information processing and quantum computing. Here we report the generation of multi-mode phenomenon through parametric amplified four- and six-wave mixing processes in a rubidium atomic ensemble. The multi-mode properties in both frequency and spatial domains are studied. On one hand, the multi-mode behavior is dominantly controlled by the intensity of external dressing effect, or nonlinear phase shift through internal dressing effect, in frequency domain; on the other hand, the multi-mode behavior is visually demonstrated from the images of the biphoton fields directly, in spatial domain. Besides, the correlation of the two output fields is also demonstrated in both domains. Our approach supports efficient applications for scalable quantum correlated imaging. PMID:28255163
Multi-mode of Four and Six Wave Parametric Amplified Process
NASA Astrophysics Data System (ADS)
Zhu, Dayu; Yang, Yiheng; Zhang, Da; Liu, Ruizhou; Ma, Danmeng; Li, Changbiao; Zhang, Yanpeng
2017-03-01
Multiple quantum modes in correlated fields are essential for future quantum information processing and quantum computing. Here we report the generation of multi-mode phenomenon through parametric amplified four- and six-wave mixing processes in a rubidium atomic ensemble. The multi-mode properties in both frequency and spatial domains are studied. On one hand, the multi-mode behavior is dominantly controlled by the intensity of external dressing effect, or nonlinear phase shift through internal dressing effect, in frequency domain; on the other hand, the multi-mode behavior is visually demonstrated from the images of the biphoton fields directly, in spatial domain. Besides, the correlation of the two output fields is also demonstrated in both domains. Our approach supports efficient applications for scalable quantum correlated imaging.
Non-adiabatic effect in quantum pumping for a spin-boson system
NASA Astrophysics Data System (ADS)
Watanabe, Kota L.; Hayakawa, Hisao
2014-11-01
We clarify the role of non-adiabatic effects in quantum pumping for a spin-boson system. When we sinusoidally control the temperatures of two reservoirs with π /2 phase difference, we find that the pumping current strongly depends on the initial condition, and thus, the current deviates from that predicted by the adiabatic treatment. We also analytically obtain the contribution of non-adiabatic effects in the pumping current proportional to Ω ^3, where Ω is the angular frequency of the temperature control. The validity of the analytic expression is verified by our numerical calculation. Moreover, we extend the steady heat fluctuation theorem to the case for slowly modulated temperatures and large transferred energies.
Exact Solution of a Many-Fermion System and Its Associated Boson Field
NASA Astrophysics Data System (ADS)
Mattis, Daniel C.; Lieb, Elliott H.
2014-10-01
Luttinger's exactly soluble model of a one-dimensional many-fermion system is discussed. We show that he did not solve his model properly because of the paradoxical fact that the density operator commutators [ρ(p), ρ(-p')], which always vanish for any finite number of particles, no longer vanish in the field-theoretic limit of a filled Dirac sea. In fact the operators ρ(p) define a boson field which is ipso facto associated with the Fermi-Dirac field. We then use this observation to solve the model, and obtain the exact (and now nontrivial) spectrum, free energy, and dielectric constant. This we also extend to more realistic interactions in an Appendix. We calculate the Fermi surface parameter ñk, and find: ∂ñk/∂k!kr = ∞ (i.e., there exists a sharp Fermi surface) only in the case of a sufficiently weak interaction.
Multiconfigurational Time-Dependent Hartree Methods for Bosonic Systems:. Theory and Applications
NASA Astrophysics Data System (ADS)
Alon, Ofir E.; Streltsov, Alexej I.; Sakmann, Kaspar; Cederbaum, Lorenz S.
2013-02-01
We review the multiconfigurational time-dependent Hartree method for bosons, which is a formally exact many-body theory for the propagation of the time dependent Schrödinger equation of N interacting identical bosons. In this approach, the time-dependent many-boson wavefunction is written as a sum of all permanents assembled from M orthogonal orbitals, where both the expansion coefficients and the permanents (orbitals) themselves are time-dependent and determined according to the Dirac-Frenkel time-dependent variational principle. In this way, a much larger effective subspace of the many-boson Hilbert space can be spanned in practice, in contrast to multiconfigurational expansions with timeindependent configurations. We also briefly discuss the extension of this method to bosonic mixtures and resonantly coupled bosonic atoms and molecules. Two applications in one dimension are presented: (i) the numerically exact solution of the time-dependent many-boson Schrödinger equation for the population dynamics in a repulsive bosonic Josephson junction is shown to deviate significantly from the predictions of the commonly used Gross-Pitaevskii equation and Bose-Hubbard model; and (ii) the many-body dynamics of a soliton train in an attractive Bose-Einstein condensate is shown to deviate substantially from the widely accepted predictions of the Gross--Pitaevskii mean-field theory.
Dupuis, N
2011-03-01
In systems with a spontaneously broken continuous symmetry, the perturbative loop expansion is plagued by infrared divergences due to the coupling between transverse and longitudinal fluctuations. As a result, the longitudinal susceptibility diverges and the self-energy becomes singular at low energy. We study the crossover from the high-energy Gaussian regime, where perturbation theory remains valid, to the low-energy Goldstone regime characterized by a diverging longitudinal susceptibility. We consider both the classical linear O (N) model and interacting bosons at zero temperature, using a variety of techniques: perturbation theory, hydrodynamic approach (i.e., for bosons, Popov's theory), large-N limit, and nonperturbative renormalization group. We emphasize the essential role of the Ginzburg momentum scale p{G}, below which the perturbative approach breaks down. Even though the action of (nonrelativistic) bosons includes a first-order time derivative term, we find remarkable similarities in the weak-coupling limit between the classical O(N) model and interacting bosons at zero temperature.
Lynx multi-mode SAR in support of NATO Unified Vision 2012 trial
NASA Astrophysics Data System (ADS)
Dunkel, R.; Verge, T.; Linnehan, R.; Doerry, A.
2013-05-01
In June 2012, General Atomics Aeronautical Systems, Inc. (GA-ASI) Reconnaissance Systems Group participated in the NATO Unified Vision 2012 (UV12) Joint ISR (JISR) Trial at Orland Main Air Station in Brekstad, Norway. GA-ASI supplied a modified King Air 200 as a Predator B/MQ-9 Reaper Remotely Piloted Aircraft (RPA) surrogate outfitted with a Lynx Block 30 Multi-mode Synthetic Aperture Radar/Ground Moving Target Indicator (SAR/GMTI), a FLIR Star SAFIRE 3800HD Electro-optical/Infrared (EO/IR) sensor, and a L-3 Tactical Common Data Link. This airborne platform was combined with GA-ASI's new System for Tactical Archival, Retrieval, and Exploitation (STARE) for full integration into the NATO ISR exploitation community. UV12 was an event sponsored by the NATO Joint Capability Group on Intelligence, Surveillance, and Reconnaissance (ISR) to focus on the interoperability of national ISR assets and improving JISR concept of operations. The Predator B RPA surrogate flew alongside multiple NATO ISR assets in nine missions that showcased the platform's all-weather ISR capabilities focusing on the Lynx SAR/GMTI and Maritime Wide Area Search (MWAS) modes. The inclusion of the STARE technology allowed GA-ASI's radar and Full Motion Video (FMV) data to be seamlessly processed and passed to joint networks where the data was fused with other NATO ISR products, resulting in a full battlefield reconnaissance picture.
Collective dynamics of multimode bosonic systems induced by weak quantum measurement
NASA Astrophysics Data System (ADS)
Mazzucchi, Gabriel; Kozlowski, Wojciech; Caballero-Benitez, Santiago F.; Mekhov, Igor B.
2016-07-01
In contrast to the fully projective limit of strong quantum measurement, where the evolution is locked to a small subspace (quantum Zeno dynamics), or even frozen completely (quantum Zeno effect), the weak non-projective measurement can effectively compete with standard unitary dynamics leading to nontrivial effects. Here we consider global weak measurement addressing collective variables, thus preserving quantum superpositions due to the lack of which path information. While for certainty we focus on ultracold atoms, the idea can be generalized to other multimode quantum systems, including various quantum emitters, optomechanical arrays, and purely photonic systems with multiple-path interferometers (photonic circuits). We show that light scattering from ultracold bosons in optical lattices can be used for defining macroscopically occupied spatial modes that exhibit long-range coherent dynamics. Even if the measurement strength remains constant, the quantum measurement backaction acts on the atomic ensemble quasi-periodically and induces collective oscillatory dynamics of all the atoms. We introduce an effective model for the evolution of the spatial modes and present an analytic solution showing that the quantum jumps drive the system away from its stable point. We confirm our finding describing the atomic observables in terms of stochastic differential equations.
Diagrammatic description of a system coupled strongly to a bosonic bath
NASA Astrophysics Data System (ADS)
Marthaler, Michael; Leppäkangas, Juha
2016-10-01
We study a system-bath description in the strong-coupling regime where it is not possible to derive a master equation for the reduced density matrix by a direct expansion in the system-bath coupling. A particular example is a bath with significant spectral weight at low frequencies. Through a unitary transformation, it can be possible to find a more suitable small expansion parameter. Within such an approach, we construct a formally exact expansion of the master equation on the Keldysh contour. We consider a system diagonally coupled to a bosonic bath and expansion in terms of a nondiagonal hopping term. The lowest-order expansion is equivalent to the so-called P (E ) theory or noninteracting blip approximation. The analysis of the higher-order contributions shows that there are two different classes of higher-order diagrams. We study how the convergence of this expansion depends on the form of the spectral function with significant weight at zero frequency.
Fermi and Non-Fermi Liquid Behavior in Quantum Impurity Systems: Conserving Slave Boson Theory
NASA Astrophysics Data System (ADS)
Kroha, Johann; Woelfle, Peter
1998-12-01
The question of Fermi liquid vs. non-Fermi liquid behavior induced by strong correlations is one of the prominent problems in metallic local moment systems. As standard models for such systems, the SU(N)× SU(M) Anderson impurity models exhibit both Fermi liquid and non-Fermi liquid behavior, depending on their symmetry. Taking the Anderson model as an example, these lectures first give an introduction to the auxiliary boson method to describe correlated systems governed by a strong, short-range electronic repulsion. It is then shown how to include the relevant low-lying excitations (coherent spin flip and charge fluctuation processes), while preserving the local gauge symmetry of the model. This amounts to a conserving T-matrix approximation (CTMA). We prove a cancellation theorem showing that the CTMA incorporates all leading and subleading infrared singularities at any given order in a self-consistent loop expansion of the free energy. As a result, the CTMA recovers the correct infrared behavior of the auxiliary particle propagators, indicating that it correctly describes both the Fermi and the non-Fermi liquid regimes of the Anderson model.
NASA Astrophysics Data System (ADS)
Geißler, Andreas; Vasić, Ivana; Hofstetter, Walter
2017-06-01
Recent experiments have shown that (quasi)crystalline phases of Rydberg-dressed quantum many-body systems in optical lattices (OL) are within reach. Rydberg systems naturally possess strong long-range interactions due to the large polarizability of Rydberg atoms. Thus a wide range of quantum phases has been predicted, such as a devil's staircase of lattice-incommensurate density wave phases as well as the more exotic lattice supersolid order for bosonic systems, as considered in our work. Guided by results in the "frozen"-gas limit, we study the ground-state phase diagram at finite hopping amplitudes and in the vicinity of resonant Rydberg driving while fully including the long-range tail of the van der Waals interaction. Simulations within real-space bosonic dynamical mean-field theory yield an extension of the devil's staircase into the supersolid regime where the competition of condensation and interaction leads to a sequence of crystalline phases.
Development of multi-mode diabatic spin-orbit models at arbitrary order
NASA Astrophysics Data System (ADS)
Weike, Thomas; Eisfeld, Wolfgang
2016-03-01
The derivation of diabatic spin-orbit (SO) Hamiltonians is presented, which are expanded in terms of nuclear coordinates to arbitrary order including the treatment of multi-mode systems, having more than one mode of the same symmetry. The derivation is based on the microscopic Breit-Pauli SO operator and the consequent utilization of time reversal and spatial symmetry transformation properties of basis functions and coordinates. The method is demonstrated for a set of 2E and 2A1 states in C3 v ∗ (double group) symmetry, once for a 3D case of one a1 and one e mode and once for a 9D case of three a1 and three e coordinates. It is shown that the general structure of the diabatic SO Hamiltonian only depends on the basis states and is strictly imposed by time reversal symmetry. The resulting matrix can be expressed easily by a power series using six parametrized structure matrices as expansion coefficients multiplied by the associated monomials in terms of symmetrized coordinates. The explicit example presented here provides a full-dimensional diabatic SO model for methyl halide cations, which will be studied in the future.
An inductorless multi-mode RF front end for GNSS receiver in 55 nm CMOS
NASA Astrophysics Data System (ADS)
Yanbin, Luo; Chengyan, Ma; Yebing, Gan; Min, Qian; Tianchun, Ye
2015-10-01
An inductorless multi-mode RF front end for a global navigation satellite system (GNSS) receiver is presented. Unlike the traditional topology of a low noise amplifier (LNA), the inductorless current-mode noise-canceling LNA is applied in this design. The high-impedance-input radio frequency amplifier (RFA) further amplifies the GNSS signals and changes the single-end signal path into fully differential. The passive mixer down-converts the signals to the intermediate frequency (IF) band and conveys the signals to the analogue blocks. The local oscillator (LO) buffer divides the output frequency of the voltage controlled oscillator (VCO) and generates 25%-duty-cycle quadrature square waves to drive the mixer. Our measurement results display that the implemented RF front end achieves good overall performance while consuming only 6.7 mA from 1.2 V supply. The input return loss is better than -26 dB and the ultra low noise figure of 1.43 dB leads to high sensitivity of the GNSS receiver. The input 1 dB compression point is -43 dBm at the high gain of 48 dB. The designed circuit is fabricated in 55 nm CMOS technology and the die area, which is much smaller than traditional circuit, is around 220 × 280 μm2.
Krummrich, Peter M; Akhtari, Simon
2014-12-01
The selection of an appropriate pump concept has a major impact on amplifier cost and power consumption. The energy efficiency of different pump concepts is compared for multi core and multi mode active fibers. In preamplifier stages, pump power density requirements derived from full C-band low noise WDM operation result in superior energy efficiency of direct pumping of individual cores in a multi core fiber with single mode pump lasers compared to cladding pumping with uncooled multi mode lasers. Even better energy efficiency is achieved by direct pumping of the core in multi mode active fibers. Complexity of pump signal combiners for direct pumping of multi core fibers can be reduced by deploying integrated components.
Dwell time algorithm for multi-mode optimization in manufacturing large optical mirrors
NASA Astrophysics Data System (ADS)
Liu, Zhenyu
2014-08-01
CCOS (Computer Controlled Optical Surfacing) is one of the most important method to manufacture optical surface. By controlling the dwell time of a polishing tool on the mirror we can get the desired material removal. As the optical surface becoming larger, traditional CCOS method can't meet the demand that manufacturing the mirror in higher efficiency and precision. This paper presents a new method using multi-mode optimization. By calculate the dwell time map of different tool in one optimization cycle, the larger tool and the small one have complementary advantages and obtain a global optimization for multi tool and multi-processing cycles. To calculate the dwell time of different tool at the same time we use multi-mode dwell time algorithm that based on matrix calculation. With this algorithm we did simulation experiment, the result shows using multi-mode optimization algorithm can improve the efficiency maintaining good precision.
Minimizing influence of multi-modes and dispersion of electromagnetic ultrasonic lamb waves.
Zhai, Guofu; Jiang, Tao; Kang, Lei; Wang, Shujuan
2010-12-01
Electromagnetic ultrasonic (EMU) Lamb waves excited by electromagnetic acoustic transducers (EMATs) possess many advantages in NDT. However, their characteristic multi-modes and dispersion are disadvantageous for inspection and restrict further improvements in their real applications. By deducing the excitation equation of EMU Lamb waves, the primary design parameters of EMATs and the characteristic equation of Lamb waves are combined, and excitation curves based on the excitation equation are plotted to aid the design of EMATs. The excitation characteristic of EMU Lamb waves on different thickness of plates is analyzed according to the excitation curves. The influence of multi-modes of EMU Lamb waves is minimized by choosing reasonable operating points and operating zones to excite a single-mode Lamb wave or multi-mode Lamb waves with identical or approximate propagation velocities. The influence of dispersion is minimized by searching corresponding points whose slope of group velocity tends to zero. The validity of the proposed method is verified by experiments.
Quantum entanglement at high temperatures? Bosonic systems in nonequilibrium steady state
NASA Astrophysics Data System (ADS)
Hsiang, Jen-Tsung; Hu, B. L.
2015-11-01
This is the second of a series of three papers examining how viable it is for entanglement to be sustained at high temperatures for quantum systems in thermal equilibrium (Case A), in nonequilibrium (Case B) and in nonequilibrium steady state (NESS) conditions (Case C). The system we analyze here consists of two coupled quantum harmonic oscillators each interacting with its own bath described by a scalar field, set at temperatures T 1 > T 2. For constant bilinear inter-oscillator coupling studied here (Case C1) owing to the Gaussian nature, the problem can be solved exactly at arbitrary temperatures even for strong coupling. We find that the valid entanglement criterion in general is not a function of the bath temperature difference, in contrast to thermal transport in the same NESS setting [1]. Thus lowering the temperature of one of the thermal baths does not necessarily help to safeguard the entanglement between the oscillators. Indeed, quantum entanglement will disappear if any one of the thermal baths has a temperature higher than the critical temperature T c, defined as the temperature above which quantum entanglement vanishes. With the Langevin equations derived we give a full display of how entanglement dynamics in this system depends on T 1, T 2, the inter-oscillator coupling and the system-bath coupling strengths. For weak oscillator-bath coupling the critical temperature T c is about the order of the inverse oscillator frequency, but for strong oscillator-bath coupling it will depend on the bath cutoff frequency. We conclude that in most realistic circumstances, for bosonic systems in NESS with constant bilinear coupling, `hot entanglement' is largely a fiction.
Improved diffusion Monte Carlo propagators for bosonic systems using Itô calculus.
Håkansson, P; Mella, M; Bressanini, Dario; Morosi, Gabriele; Patrone, Marta
2006-11-14
The construction of importance sampled diffusion Monte Carlo (DMC) schemes accurate to second order in the time step is discussed. A central aspect in obtaining efficient second order schemes is the numerical solution of the stochastic differential equation (SDE) associated with the Fokker-Plank equation responsible for the importance sampling procedure. In this work, stochastic predictor-corrector schemes solving the SDE and consistent with Itô calculus are used in DMC simulations of helium clusters. These schemes are numerically compared with alternative algorithms obtained by splitting the Fokker-Plank operator, an approach that we analyze using the analytical tools provided by Ito; calculus. The numerical results show that predictor-corrector methods are indeed accurate to second order in the time step and that they present a smaller time step bias and a better efficiency than second order split-operator derived schemes when computing ensemble averages for bosonic systems. The possible extension of the predictor-corrector methods to higher orders is also discussed.
Domain-wall melting in ultracold-boson systems with hole and spin-flip defects
NASA Astrophysics Data System (ADS)
Halimeh, Jad C.; Wöllert, Anton; McCulloch, Ian; Schollwöck, Ulrich; Barthel, Thomas
2014-06-01
Quantum magnetism is a fundamental phenomenon of nature. As of late, it has garnered a lot of interest because experiments with ultracold atomic gases in optical lattices could be used as a simulator for phenomena of magnetic systems. A paradigmatic example is the time evolution of a domain-wall state of a spin-1/2 Heisenberg chain, the so-called domain-wall melting. The model can be implemented by having two species of bosonic atoms with unity filling and strong on-site repulsion U in an optical lattice. In this paper, we study the domain-wall melting in such a setup on the basis of the time-dependent density matrix renormalization group (tDMRG). We are particularly interested in the effects of defects that originate from an imperfect preparation of the initial state. Typical defects are holes (empty sites) and flipped spins. We show that the dominating effects of holes on observables like the spatially resolved magnetization can be taken account of by a linear combination of spatially shifted observables from the clean case. For sufficiently large U, further effects due to holes become negligible. In contrast, the effects of spin flips are more severe as their dynamics occur on the same time scale as that of the domain-wall melting itself. It is hence advisable to avoid preparation schemes that are based on spin flips.
Multi-mode TES Bolometer Optimization for the LSPE-SWIPE Instrument
NASA Astrophysics Data System (ADS)
Gualtieri, R.; Battistelli, E. S.; Cruciani, A.; de Bernardis, P.; Biasotti, M.; Corsini, D.; Gatti, F.; Lamagna, L.; Masi, S.
2016-08-01
In this paper, we explore the possibility of using transition edge sensor (TES) detectors in multi-mode configuration in the focal plane of the Short Wavelength Instrument for the Polarization Explorer (SWIPE) of the balloon-borne polarimeter Large-Scale Polarization Explorer (LSPE) for the Cosmic Microwave Background (CMB) polarization. This study is motivated by the fact that maximizing the sensitivity of TES bolometers, under the augmented background due to the multi-mode design, requires a non-trivial choice of detector parameters. We evaluate the best parameter combination taking into account scanning strategy, noise constraints, saturation power, and operating temperature of the cryostat during the flight.
Zhang, Qinjin; Liu, Yancheng; Zhao, Youtao; Wang, Ning
2016-03-01
Multi-mode operation and transient stability are two problems that significantly affect flexible microgrid (MG). This paper proposes a multi-mode operation control strategy for flexible MG based on a three-layer hierarchical structure. The proposed structure is composed of autonomous, cooperative, and scheduling controllers. Autonomous controller is utilized to control the performance of the single micro-source inverter. An adaptive sliding-mode direct voltage loop and an improved droop power loop based on virtual negative impedance are presented respectively to enhance the system disturbance-rejection performance and the power sharing accuracy. Cooperative controller, which is composed of secondary voltage/frequency control and phase synchronization control, is designed to eliminate the voltage/frequency deviations produced by the autonomous controller and prepare for grid connection. Scheduling controller manages the power flow between the MG and the grid. The MG with the improved hierarchical control scheme can achieve seamless transitions from islanded to grid-connected mode and have a good transient performance. In addition the presented work can also optimize the power quality issues and improve the load power sharing accuracy between parallel VSIs. Finally, the transient performance and effectiveness of the proposed control scheme are evaluated by theoretical analysis and simulation results.
Small-signal analysis of ultra-high-speed 30 GHz VCSELs using an advanced multi-mode approach
NASA Astrophysics Data System (ADS)
Hamad, Wissam; Bou Sanayeh, Marwan; Hamad, Hassan; Hamad, Mustapha; Georges, Semaan; Hofmann, Werner
2017-05-01
Vertical-cavity surface-emitting lasers (VCSELs) have emerged as a pioneering solution for many high-speed data communication challenges. Therefore, higher bandwidth optical interconnects with data rates in the range of 100 Gbit/s require directly modulated VCSELs with ultimate speed ratings. The small-signal modulation response of a VCSEL can be isolated from the entire system, thus providing accurate information on the intrinsic laser dynamics. Until now, it is assumed that the dynamic behavior of oxide-confined multi-mode VCSELs can be fully modeled using the single-mode rate equations developed for edge-emitters, even though the deviation between the single-mode based model and the measured data is substantially large. Using an advanced theoretical approach, rate equations for multi-mode VCSELs were developed and the small-signal modulation response of ultra-high speed devices with split carrier reservoirs corresponding with the resonating modes were analyzed. Based on this theoretical work, and including gain compression in the model, the analyzed VCSELs showed modulation bandwidth around and exceeding 30 GHz. The common set of figures of merit is extended consistently to explain dynamic properties caused by the coupling of the different reservoirs. Furthermore, beside damping and relaxation oscillation frequency, the advanced model, with gain compression included, can reveal information on the photon lifetime and highlights high-speed effects such as reduced damping in VCSELs due to a negative gain compression factor.
NASA Astrophysics Data System (ADS)
Berrada, K.; Al-Rajhi, M. A.
2017-10-01
In this paper, we present a detailed study on the evolution of some measures of nonclassicality and entanglement in the framework of the interaction between a superconducting qubit and deformed bosonic fields under decoherence effect. We compare the dynamical behavior of the different quantum quantifiers by exploiting a large set of nonlinear bosonic fields that are characterized by the deformation parameter. Additionally, we demonstrate how the connection between the appearance of the nonlinearity in the deformed field and the quantum information quantifiers. The time correlation between entropy squeezing, purity, and entanglement is examined in terms of the physical parameters involved in the whole system. Lastly, we explore the exact ranges of the physical parameters in order to combat the decoherence effect and maintain high amount of entanglement during the time evolution.
Time-dependent restricted-active-space self-consistent-field theory for bosonic many-body systems
NASA Astrophysics Data System (ADS)
Lévêque, Camille; Bojer Madsen, Lars
2017-04-01
We develop an ab initio time-dependent wavefunction based theory for the description of a many-body system of cold interacting bosons. Like the multi-configurational time-dependent Hartree method for bosons (MCTDHB), the theory is based on a configurational interaction Ansatz for the many-body wavefunction with time-dependent self-consistent-field orbitals. The theory generalizes the MCTDHB method by incorporating restrictions on the active space of the orbital excitations. The restrictions are specified based on the physical situation at hand. The equations of motion of this time-dependent restricted-active-space self-consistent-field (TD-RASSCF) theory are derived. The similarity between the formal development of the theory for bosons and fermions is discussed. The restrictions on the active space allow the theory to be evaluated under conditions where other wavefunction based methods due to exponential scaling in the numerical effort cannot, and to clearly identify the excitations that are important for an accurate description, significantly beyond the mean-field approach. For ground state calculations we find it to be important to allow a few particles to have the freedom to move in many orbitals, an insight facilitated by the flexibility of the restricted-active-space Ansatz. Moreover, we find that a high accuracy can be obtained by including only even excitations in the many-body self-consistent-field wavefunction. Time-dependent simulations of harmonically trapped bosons subject to a quenching of their noncontact interaction, show failure of the mean-field Gross-Pitaevskii approach within a fraction of a harmonic oscillation period. The TD-RASSCF theory remains accurate at much reduced computational cost compared to the MCTDHB method. Exploring the effect of changes of the restricted-active-space allows us to identify that even self-consistent-field excitations are mainly responsible for the accuracy of the method.
Chen, Zhao-Qiu; Zhao, Feng-Ling; Zhu, Jian; Li, Wan-Hu; Fu, Zheng; Hu, Xu-Dong
2008-07-01
This paper introduces a display module which can be used on multi-mode medical images. The module has a small size and can be easily used for point-selecting puncture diagnosis and treatment, and registration for image fusion control points.
WET-NZ Multi-Mode Wave Energy Converter Advancement Project
Klure, Justin
2011-11-01
Presentation from the 2011 Water Peer Review in which the principal investigator discussed the next steps to verify a multi-mode functionality of the WET-NZ device. This included overview of the approaches taken to perform wave tank testing, open ocean deployment, synthesis and analysis.
NASA Astrophysics Data System (ADS)
Marino, Eduardo
The electron, discovered by Thomson by the end of the nineteenth century, was the first experimentally observed particle. The Weyl fermion, though theoretically predicted since a long time, was observed in a condensed matter environment in an experiment reported only a few weeks ago. Is there any linking thread connecting the first and the last observed fermion (quasi)particles? The answer is positive. By generalizing the method known as bosonization, the first time in its full complete form, for a spacetime with 3+1 dimensions, we are able to show that both electrons and Weyl fermions can be expressed in terms of the same boson field, namely the Kalb-Ramond anti-symmetric tensor gauge field. The bosonized form of the Weyl chiral currents lead to the angle-dependent magneto-conductance behavior observed in these systems.
An alternative multi-mode SAR for RADARSAT
NASA Technical Reports Server (NTRS)
Raney, R. K.
1986-01-01
The RADARSAT project was asked by the Canadian government in the spring of 1986 to design for reduced costs and increased radar performance as compared to the well-known baseline design. Both the Project Office and Canadian industry (lead by SPAR Aerospace of Montreal) have undertaken to meet this request, with a proposal to cabinet to be submitted in the fall of 1986. One alternative SAR concept is outlined which is under consideration for a revised RADARSAT configuration. The radar system described uses two frequencies (C&L band) over four possible modes: near range swath; far range swath; wide swath; and high resolution. Good sensitivity, resolution, and coverage are obtained with modest power and data rates. The antenna systems are relatively simple. Indeed, no break-through technological developments are needed. The design allows several mode combinations for simultaneous data collection or performance enhancement. The principal parameters are described. A nominal mean altitude of 700 km is assumed.
Learning effects on muscle modes and multi-mode postural synergies.
Asaka, Tadayoshi; Wang, Yun; Fukushima, Junko; Latash, Mark L
2008-01-01
We used the framework of the uncontrolled manifold hypothesis to explore the effects of practice on the composition of muscle groups (M-modes) and multi-M-mode synergies stabilizing the location of the center of pressure (COP). In particular, we tested a hypothesis that practice could lead to a transition from co-contraction muscle activation patterns to reciprocal patterns. We also tested a hypothesis that new sets of M-modes would form stronger synergies stabilizing COP location. Subjects practiced load release tasks for five days while standing on a board with a narrow support surface (unstable board). Their M-modes and indices of multi-M-mode synergies were computed during standing without instability and during standing on an unstable board before practice, in the middle of practice, and at the end of practice. During standing without instability, subjects showed two consistent M-modes uniting dorsal and ventral muscles of the body respectively (reciprocal modes). While standing on an unstable board, prior to practice, subjects commonly showed M-modes uniting muscle pairs with opposing actions at major leg joints-co-contraction modes. Such sets of M-modes failed to stabilize the COP location in the anterior-posterior direction. Practice led to better task performance reflected in fewer incidences of lost balance. This was accompanied by a drop in the occurrence of co-contraction M-modes and the emergence of multi-mode synergies stabilizing the COP location. We conclude that the central nervous system uses flexible sets of elemental variables (modes) to ensure stable trajectories of important performance variables (such as COP location). Practice can lead to adjustments in both the composition of M-modes and M-mode co-variation patterns resulting in stronger synergies stabilizing COP location.
NASA Astrophysics Data System (ADS)
Belvedere, L. V.; Amaral, R. L. P. G.; de Queiroz, A. F.
We use the two-dimensional Fermion-Boson mapping to perform a field theory analysis of the effective Lagrangian model for incommensurate charge-density waves (ICDW) in one-dimensional systems. We consider an approach in which both the phase of the complex phonon field and the electron field are dynamical degrees of freedom contributing to the quantum dynamics and symmetry-related features of the ICDW phenomenon. We obtain the bosonized and fermionized versions of the effective electron-phonon Lagrangian. The phase of the phonon field and the phase of the bosonized chiral density of the electron field condense as a soliton order parameter, carrying neither the charge nor the chirality of the electron-phonon system, leading to a periodic sine-Gordon potential. The phonon field is fermionized in terms of a chiral fermionic condensate and the effective model is mapped into the chiral Gross-Neveu (GN) model with two Fermi field species. The linked electron-phonon symmetry of the ICDW system is mapped into the chiral symmetry of the GN model. Within the functional integral formulation, we obtain for the vacuum expectation value of the phonon field < φ > = 0 and < φ φast > ≠ 0, due to the charge selection rule associated with the chiral electron-phonon symmetry. We show that the two-point correlation function of the phonon field satisfies the cluster decomposition property, as required by the chiral symmetry of the underlying GN model. The quantum description of the ICDW corresponds to charge transport through the lattice, due to the propagation of a ``Goldstone mode'' carrying the effective charge of the electron-phonon system, is accomplished by an electron-lattice energy redistribution. This accounts for a dynamical Peierls's energy gap generation.
Number of spin I states for bosons
Zhang, L. H.; Zhao, Y. M.; Jia, L. Y.; Arima, A.
2008-01-15
We study number of spin I states for bosons in this article. We extend Talmi's recursion formulas for number of states with given spin I to boson systems, and we prove empirical formulas for five bosons by using these recursions. We obtain number of states with given spin I and F spin for three and four bosons by using sum rules of six-j and nine-j symbols. We also present empirical formulas of states for d bosons with given spin I and F=F{sub max}-1 and F{sub max}-2.0.
Chiral Bosonization of Superconformal Ghosts
NASA Technical Reports Server (NTRS)
Shi, Deheng; Shen, Yang; Liu, Jinling; Xiong, Yongjian
1996-01-01
We explain the difference of the Hilbert space of the superconformal ghosts (beta,gamma) system from that of its bosonized fields phi and chi. We calculate the chiral correlation functions of phi, chi fields by inserting appropriate projectors.
Color digital holography using speckle illumination by means of a multi-mode fiber
NASA Astrophysics Data System (ADS)
Funamizu, Hideki; Shimoma, Shohei; Aizu, Yoshihisa
2014-02-01
We present color digital holography using speckle illumination by means of a multi-mode fiber. In this technique, speckle fields emitted from the fiber are used as both a reference wave and a wavefront illuminating an object. For three wavelengths, the interference patterns of two coherent waves are recorded as digital holograms on a CCD camera. A speckle method is used for suppressing DC terms and reducing a twin image in an in-line color digital holography. The speckle fields are changed by vibrating the multi-mode fiber using a vibrator, and a number of holograms are acquired to average reconstructed images. The dependence of the averaged number of holograms on color quality of reconstructed images is evaluated by chromaticity coordinates and color differences in colorimetry.
Evolution of multi-mode operation in vertical-external-cavity surface-emitting lasers.
Wichmann, Matthias; Shakfa, Mohammad Khaled; Zhang, Fan; Heinen, Bernd; Scheller, Maik; Rahimi-Iman, Arash; Stolz, Wolfgang; Moloney, Jerome V; Koch, Stephan W; Koch, Martin
2013-12-30
The longitudinal multi-mode emission in a vertical-external-cavity surface-emitting laser is investigated using both single shot streak camera measurements and interferometric measurement techniques. For this, the laser is operated in the single- and two-color emission regime using both an etalon and a free-running configuration without etalon, respectively. The laser emission is analyzed with respect to pump power and output coupling losses for a long and for a short resonator. We observe a steep increase of emission bandwidth close to the laser threshold and monitor the transition between longitudinal single- and multi-mode operation. Additionally, the results indicate that a stable two-color operation is related to a sufficiently high number of oscillating longitudinal modes within each color.
Unconventional geometric logic gate in a strong-driving-assisted multi-mode cavity
NASA Astrophysics Data System (ADS)
Pan, Chang-Ning; Yang, Di-Wu; Zhao, Xue-Hui; Fang, Mao-Fa
2010-08-01
We propose a scheme to implement an unconventional geometric logic gate separately in a two-mode cavity and a multi-mode cavity assisted by a strong classical driving field. The effect of the cavity decay is included in the investigation. The numerical calculation is carried out, and the result shows that our scheme is more tolerant to cavity decay than the previous one because the time consumed for finishing the logic gate is doubly reduced.
NASA Astrophysics Data System (ADS)
Barkhofen, Sonja; Bartley, Tim J.; Sansoni, Linda; Kruse, Regina; Hamilton, Craig S.; Jex, Igor; Silberhorn, Christine
2017-01-01
Sampling the distribution of bosons that have undergone a random unitary evolution is strongly believed to be a computationally hard problem. Key to outperforming classical simulations of this task is to increase both the number of input photons and the size of the network. We propose driven boson sampling, in which photons are input within the network itself, as a means to approach this goal. We show that the mean number of photons entering a boson sampling experiment can exceed one photon per input mode, while maintaining the required complexity, potentially leading to less stringent requirements on the input states for such experiments. When using heralded single-photon sources based on parametric down-conversion, this approach offers an ˜e -fold enhancement in the input state generation rate over scattershot boson sampling, reaching the scaling limit for such sources. This approach also offers a dramatic increase in the signal-to-noise ratio with respect to higher-order photon generation from such probabilistic sources, which removes the need for photon number resolution during the heralding process as the size of the system increases.
NASA Astrophysics Data System (ADS)
Tomchenko, Maksim
2017-02-01
We show that the system of Gaudin’s equations for quasimomenta k j , which describes a one-dimensional system of spinless point bosons with zero boundary conditions, has the unique real solution for each set of quantum numbers n j .
Two-level systems and boson peak remain stable in 110-million-year-old amber glass.
Pérez-Castañeda, Tomás; Jiménez-Riobóo, Rafael J; Ramos, Miguel A
2014-04-25
The two most prominent and ubiquitous features of glasses at low temperatures, namely the presence of tunneling two-level systems and the so-called boson peak in the reduced vibrational density of states, are shown to persist essentially unchanged in highly stabilized glasses, contrary to what was usually envisaged. Specifically, we have measured the specific heat of 110 million-year-old amber samples from El Soplao (Spain), both at very low temperatures and around the glass transition Tg. In particular, the amount of two-level systems, assessed at the lowest temperatures, was surprisingly found to be exactly the same for the pristine hyperaged amber as for the, subsequently, partially and fully rejuvenated samples.
Jin, Jinshuang; Welack, Sven; Luo, JunYan; Li, Xin-Qi; Cui, Ping; Xu, Rui-Xue; Yan, YiJing
2007-04-07
A hierarchical equations of motion formalism for a quantum dissipation system in a grand canonical bath ensemble surrounding is constructed on the basis of the calculus-on-path-integral algorithm, together with the parametrization of arbitrary non-Markovian bath that satisfies fluctuation-dissipation theorem. The influence functionals for both the fermion or boson bath interaction are found to be of the same path integral expression as the canonical bath, assuming they all satisfy the Gaussian statistics. However, the equation of motion formalism is different due to the fluctuation-dissipation theories that are distinct and used explicitly. The implications of the present work to quantum transport through molecular wires and electron transfer in complex molecular systems are discussed.
Superradiant phase transition in a model of three-level-Λ systems interacting with two bosonic modes
NASA Astrophysics Data System (ADS)
Hayn, Mathias; Emary, Clive; Brandes, Tobias
2012-12-01
We consider an ensemble of three-level particles in Lambda configuration interacting with two bosonic modes. The Hamiltonian has the form of a generalized Dicke model. We show that in the thermodynamic limit this model supports a superradiant quantum phase transition. Remarkably, this can be both a first- and a second-order phase transition. A connection of the phase diagram to the symmetries of the Hamiltonian is also given. In addition, we show that this model can describe atoms interacting with an electromagnetic field in which the microscopic Hamiltonian includes a diamagnetic contribution. Even though the parameters of the atomic system respect the Thomas-Reiche-Kuhn sum rule, the system still shows a superradiant phase transition.
NASA Astrophysics Data System (ADS)
Mele, Salvatore
2004-12-01
The high-energy and high-luminosity data-taking campaigns of the LEP e+e- collider provided the four collaborations, ALEPH, DELPHI, L3 and OPAL, with about 50000 W-boson pairs and about a thousand singly produced W bosons. This unique data sample has an unprecedented reach in probing some aspects of the Standard Model of the electroweak interactions, and this article reviews several achievements in the understanding of W-boson physics at LEP. The measurements of the cross-sections for W-boson production are discussed, together with their implication on the existence of the coupling between Z and W bosons. The precision measurements of the magnitude of triple gauge-boson couplings are presented. The obervation of the longitudinal helicity component of the W-boson spin, related to the mechanism of electroweak symmetry breaking, is described together with the techniques used to probe the CP and CPT symmetries in the W-boson system. A discussion on the intricacies of the measurment of the mass of the W boson, whose knowledge is indispensable to test the internal consistency of the Standard Model and estimate the mass of the Higgs boson, concludes this review.
NASA Astrophysics Data System (ADS)
Martin, André; Roy, S. M.
1989-12-01
The N particle hamiltonian Σi=1N(pi2+m2)1/2-Σi
NASA Astrophysics Data System (ADS)
Alvermann, A.; Edwards, D. M.; Fehske, H.
2010-04-01
In classical Drude theory the conductivity is determined by the mass of the propagating particles and the mean free path between two scattering events. For a quantum particle this simple picture of diffusive transport loses relevance if strong correlations dominate the particle motion. We study a situation where the propagation of a fermionic particle is possible only through creation and annihilation of local bosonic excitations. This correlated quantum transport process is outside the Drude picture, since one cannot distinguish between free propagation and intermittent scattering. The characterization of transport is possible using the Drude weight obtained from the f-sum rule, although its interpretation in terms of free mass and mean free path breaks down. For the situation studied we calculate the Green's function and Drude weight using a Green's functions expansion technique, and discuss their physical meaning.
NASA Astrophysics Data System (ADS)
McGuire, J. B.
2011-12-01
There is a body of conventional wisdom that holds that a solvable quantum problem, by virtue of its solvability, is pathological and thus irrelevant. It has been difficult to refute this view owing to the paucity of theoretical constructs and experimental results. Recent experiments involving equivalent ions trapped in a spatial conformation of extreme anisotropic confinement (longitudinal extension tens, hundreds or even thousands of times transverse extension) have modified the view of relevancy, and it is now possible to consider systems previously thought pathological, in particular point Bosons that repel in one dimension. It has been difficult for the experimentalists to utilize existing theory, mainly due to long-standing theoretical misunderstanding of the relevance of the permutation group, in particular the non-commutativity of translations (periodicity) and transpositions (permutation). This misunderstanding is most easily rectified in the case of repelling Bosons.
NASA Astrophysics Data System (ADS)
Xu, Yejun; Liang, Xiudong; Cheng, Jianming; Tai, Yunjiao; Song, Jun
2014-03-01
We present a simple proposal to measure arbitrary multi-mode entangled traveling field state based on a Mach-Zehnder interferometer in theory. Our method directly yields the characteristic function of the Wigner function without a demanding data analysis and can be easily carried out by recent technological advances. Especially, it is a very effective reconstruction proposal for an entangled traveling field with a small number of modes from the experimental point of view. We demonstrate the scheme for the example of a two-mode squeezed vacuum state to illustrate how similar the reconstructed state is to the ideal one via controlling the values of phase shifts.
Demonstration of polarization modulated signals in a multi-mode GdFe-silica hybrid fiber
NASA Astrophysics Data System (ADS)
Nishibayashi, K.; Yoneda, H.; Kuga, K.; Matsuda, T.; Munekata, H.
2015-04-01
We fabricate a hybrid fiber composed of a multi-mode, silica-based fiber and a GdFe thin film adjacent to each other. Magneto-optical (MO) signals modulated by AC magnetic fields on the GdFe layer are detected at the output pupil of the fiber, showing that the polarization state of the propagated light in the mixed-mode condition can be well defined. We find that local modulation of magnetization at different positions of the GdFe layer results in MO signals at the different position of the output, showing the spatial de-multiplexing of polarization modulated signals.
NASA Astrophysics Data System (ADS)
Liu, Fu; Guo, Tuan; Shang, Libin; Zhang, Zhaochuan; Du, Fa; Guan, Bai-Ou; Albert, Jacques
2014-05-01
The polarimetric sensing characteristics of multi-mode-fiber based tilted fiber Bragg grating (MMF-TFBG) have been analyzed and experimentally demonstrated. The physical "enlarged" fiber core enables the tilted gratings to excite multi high-order core modes with significantly different polarization dependence and well-defined "comb" profiles which are spectrally separated at different wavelength. Orientation-recognized twist/rotation measurement (-90o to 90o) has been achieved with sensitivity of 0.075 dB/deg by using a cost-effective double-path power detection (power monitoring of two orthogonal-polarimetric odd core-modes, i.e. LP11 and LP12).
Rate-equation model for multi-mode semiconductor lasers with spatial hole burning.
Lenstra, Daan; Yousefi, Mirvais
2014-04-07
We present a set of rate equations for the modal amplitudes and carrier-inversion moments that describe the deterministic multi-mode dynamics of a semiconductor laser due to spatial hole burning. Mutual interactions among the lasing modes, induced by high- frequency modulations of the carrier distribution, are included by carrier-inversion moments for which rate equations are given as well. We derive the Bogatov effect of asymmetric gain suppression in semiconductor lasers and illustrate the potential of the model for a two and three-mode laser by numerical and analytical methods.
NASA Astrophysics Data System (ADS)
Tomchenko, Maksim
2017-01-01
We compare two approaches to the construction of the thermodynamics of a one-dimensional periodic system of spinless point bosons: the Yang-Yang approach and a new approach proposed by the author. In the latter, the elementary excitations are introduced so that there is only one type of excitations (as opposed to Lieb's approach with two types of excitations: particle-like and hole-like). At the weak coupling, these are the excitations of the Bogolyubov type. The equations for the thermodynamic quantities in these approaches are different, but their solutions coincide (this is shown below and is the main result). Moreover, the new approach is simpler. An important point is that the thermodynamic formulae in the new approach for any values of parameters are formulae for an ensemble of quasiparticles with Bose statistics, whereas a formulae in the traditional Yang-Yang approach have the Fermi-like one-particle form.
Hernández-Quiroz, Saúl; Benet, Luis
2010-03-01
We study the nearest-neighbor distributions of the k -body embedded ensembles of random matrices for n bosons distributed over two-degenerate single-particle states. This ensemble, as a function of k , displays a transition from harmonic-oscillator behavior (k=1) to random-matrix-type behavior (k=n) . We show that a large and robust quasidegeneracy is present for a wide interval of values of k when the ensemble is time-reversal invariant. These quasidegenerate levels are Shnirelman doublets which appear due to the integrability and time-reversal invariance of the underlying classical systems. We present results related to the frequency in the spectrum of these degenerate levels in terms of k and discuss the statistical properties of the splittings of these doublets.
NASA Technical Reports Server (NTRS)
Choi, Benjamin; Morrison, Carlos; Min, James
2009-01-01
The Structural Dynamics and. Mechanics branch (RXS) is developing smart adaptive structures to improve fan blade damping at resonances using piezoelectric (PE) transducers. In this presentation, only one shunted PE transducer was used to demonstrate active control of multi-mode blade resonance damping on a titanium alloy (Ti-6A1-4V) flat plate model, regardless of bending, torsion, and 2-stripe modes. This work would have a significant impact on the conventional passive shunt damping world because the standard feedback control design tools can now be used to design and implement electric shunt for vibration control. In other words, the passive shunt circuit components using massive inductors and. resistors for multi-mode resonance control can be replaced with digital codes. Furthermore, this active approach with multi patches can simultaneously control several modes in the engine operating range. Dr. Benjamin Choi presented the analytical and experimental results from this work at the Propulsion-Safety and. Affordable Readiness (P-SAR) Conference in March, 2009.
A baseband LPF for GSM, TD-SCDMA and WCDMA multi-mode transmitters
NASA Astrophysics Data System (ADS)
Yongchang, Yu; Kefeng, Han; Lifang, Wang; Xi, Tan; Hao, Min
2011-02-01
This paper describes a low-pass reconfigurable baseband filter for GSM, TD-SCDMA and WCDMA multi-mode transmitters. To comply with 3GPP emission mask and limit TX leakage at the RX band, the out-of-band noise performance is optimized. Due to the distortion caused by the subthreshold leakage current of the switches used in capacitor array, a capacitor bypass technique is proposed to improve the filter's linearity. An automatic frequency tuning circuit is adopted to compensate the cut-off frequency variation. Simulation results show that the filter achieves an in-band input-referred third-order intercept point (IIP3) of 47 dBm at 1.2-V power supply and the out-of-band noise can meet TX SAW-less requirement for WCDMA & TD-SCDMA. The baseband filter incorporates -40 to 0 dB programmable gain control that is accurately variable in 0.5 dB steps. The filter's cut-off frequency can be reconfigured for GSM/TD-SCDMA/WCDMA multi-mode transmitter. The implemented baseband filter draws 3.6 mA from a 1.2-V supply in a 0.13 μm CMOS process.
NASA Astrophysics Data System (ADS)
Yin, Biwei; Liang, Chia-Pin; Vuong, Barry; Tearney, Guillermo J.
2017-02-01
Conventional OCT images, obtained using a focused Gaussian beam have a lateral resolution of approximately 30 μm and a depth of focus (DOF) of 2-3 mm, defined as the confocal parameter (twice of Gaussian beam Rayleigh range). Improvement of lateral resolution without sacrificing imaging range requires techniques that can extend the DOF. Previously, we described a self-imaging wavefront division optical system that provided an estimated one order of magnitude DOF extension. In this study, we further investigate the properties of the coaxially focused multi-mode (CAFM) beam created by this self-imaging wavefront division optical system and demonstrate its feasibility for real-time biological tissue imaging. Gaussian beam and CAFM beam fiber optic probes with similar numerical apertures (objective NA≈0.5) were fabricated, providing lateral resolutions of approximately 2 μm. Rigorous lateral resolution characterization over depth was performed for both probes. The CAFM beam probe was found to be able to provide a DOF that was approximately one order of magnitude greater than that of Gaussian beam probe. By incorporating the CAFM beam fiber optic probe into a μOCT system with 1.5 μm axial resolution, we were able to acquire cross-sectional images of swine small intestine ex vivo, enabling the visualization of subcellular structures, providing high quality OCT images over more than a 300 μm depth range.
Quantum Fisher Information of Driven Multi-particle Systems in Structured Bosonic Reservoirs
NASA Astrophysics Data System (ADS)
Yan, Kai; Xie, Yan-Qing; Huang, Yu-Meng; Hao, Xiang
2017-03-01
We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms. Supported by the National Natural Science Foundation of China under Grant No. 11274054, the Creative Project of Graduate in University of Suzhou Science and Technology in No. SKCX16-006, the Innovation Project of Graduate Education of Jiangsu Province No. JGLX15-150
NASA Astrophysics Data System (ADS)
Volkoff, Tyler James
In this dissertation, I analyze certain problems in the following areas: 1) quantum dynamical phenomena in macroscopic systems of interacting, degenerate bosons (Parts II, III, and V), and 2) measures of macroscopicity for a large class of two-branch superposition states in separable Hilbert space (Part IV). Part I serves as an introduction to important concepts recurring in the later Parts. In Part II, a microscopic derivation of the effective action for the relative phase of driven, aperture-coupled reservoirs of weakly-interacting condensed bosons from a (3 + 1)D microscopic model with local U(1) gauge symmetry is presented. The effective theory is applied to the transition from linear to sinusoidal current vs. phase behavior observed in recent experiments on liquid 4He driven through nanoaperture arrays. Part III discusses path-integral Monte Carlo (PIMC) numerical simulations of quantum hydrodynamic properties of reservoirs of He II communicating through simple nanoaperture arrays. In addition to calculating the local superfluid density in these systems, new estimators for hydrodynamic observables and novel methods for extracting the length scale characterizing the decay of superfluidity at the system boundary from PIMC data are introduced with the aim of exploring the mechanism of superfluid weak-link formation in nanoscale containers. Part IV consists of an analysis of macroscopicity measures for a large class of Schrodinger cat states of N-mode photonic systems. For cat states of this class, it is shown that a well-known measure of superposition size based on the optimal distinguishability of the branches and another based on metrological usefulness of the superposition relative to its branches agree (i.e., designate the same superpositions as macroscopic) when the inner product of the branches of the superposition is sufficiently small. For certain superpositions in this class, a technique is presented for deriving a state-specific metrological
Elzoghby, Mostafa; Li, Fu; Arafa, Ibrahim I; Arif, Usman
2017-04-18
Information fusion from multiple sensors ensures the accuracy and robustness of a navigation system, especially in the absence of global positioning system (GPS) data which gets degraded in many cases. A way to deal with multi-mode estimation for a small fixed wing unmanned aerial vehicle (UAV) localization framework is proposed, which depends on utilizing a Luenberger observer-based linear matrix inequality (LMI) approach. The proposed estimation technique relies on the interaction between multiple measurement modes and a continuous observer. The state estimation is performed in a switching environment between multiple active sensors to exploit the available information as much as possible, especially in GPS-denied environments. Luenberger observer-based projection is implemented as a continuous observer to optimize the estimation performance. The observer gain might be chosen by solving a Lyapunov equation by means of a LMI algorithm. Convergence is achieved by utilizing the linear matrix inequality (LMI), based on Lyapunov stability which keeps the dynamic estimation error bounded by selecting the observer gain matrix (L). Simulation results are presented for a small UAV fixed wing localization problem. The results obtained using the proposed approach are compared with a single mode Extended Kalman Filter (EKF). Simulation results are presented to demonstrate the viability of the proposed strategy.
Elzoghby, Mostafa; Li, Fu; Arafa, Ibrahim. I.; Arif, Usman
2017-01-01
Information fusion from multiple sensors ensures the accuracy and robustness of a navigation system, especially in the absence of global positioning system (GPS) data which gets degraded in many cases. A way to deal with multi-mode estimation for a small fixed wing unmanned aerial vehicle (UAV) localization framework is proposed, which depends on utilizing a Luenberger observer-based linear matrix inequality (LMI) approach. The proposed estimation technique relies on the interaction between multiple measurement modes and a continuous observer. The state estimation is performed in a switching environment between multiple active sensors to exploit the available information as much as possible, especially in GPS-denied environments. Luenberger observer-based projection is implemented as a continuous observer to optimize the estimation performance. The observer gain might be chosen by solving a Lyapunov equation by means of a LMI algorithm. Convergence is achieved by utilizing the linear matrix inequality (LMI), based on Lyapunov stability which keeps the dynamic estimation error bounded by selecting the observer gain matrix (L). Simulation results are presented for a small UAV fixed wing localization problem. The results obtained using the proposed approach are compared with a single mode Extended Kalman Filter (EKF). Simulation results are presented to demonstrate the viability of the proposed strategy. PMID:28420214
NASA Astrophysics Data System (ADS)
Lan, Tian; Kong, Liang; Wen, Xiao-Gang
2017-06-01
In 2+1-dimensional space-time, gapped quantum states are always gapped quantum liquids (GQL) which include both topologically ordered states (with long range entanglement) and symmetry protected topological (SPT) states (with short range entanglement). In this paper, we propose a classification of 2+1D GQLs for both bosonic and fermionic systems: 2+1D bosonic/fermionic GQLs with finite on-site symmetry are classified by nondegenerate unitary braided fusion categories over a symmetric fusion category (SFC) E , abbreviated as UMTC/E, together with their modular extensions and total chiral central charges. In our classification, SFC E describes the symmetry, which is Rep(G ) for bosonic symmetry G , or sRep(Gf) for fermionic symmetry Gf. As a special case of the above result, we find that the modular extensions of Rep(G ) classify the 2+1D bosonic SPT states of symmetry G , while the c =0 modular extensions of sRep(Gf) classify the 2+1D fermionic SPT states of symmetry Gf. Many fermionic SPT states are studied based on the constructions from free-fermion models. But free-fermion constructions cannot produce all fermionic SPT states. Our classification does not have such a drawback. We show that, for interacting 2+1D fermionic systems, there are exactly 16 superconducting phases with no symmetry and no fractional excitations (up to E8 bosonic quantum Hall states). Also, there are exactly 8 Z2×Z2f -SPT phases, 2 Z8f-SPT phases, and so on. Besides, we show that two topological orders with identical bulk excitations and central charge always differ by the stacking of the SPT states of the same symmetry.
ERIC Educational Resources Information Center
Veltman, Martinus J. G.
1986-01-01
Reports recent findings related to the particle Higgs boson and examines its possible contribution to the standard mode of elementary processes. Critically explores the strengths and uncertainties of the Higgs boson and proposed Higgs field. (ML)
ERIC Educational Resources Information Center
Veltman, Martinus J. G.
1986-01-01
Reports recent findings related to the particle Higgs boson and examines its possible contribution to the standard mode of elementary processes. Critically explores the strengths and uncertainties of the Higgs boson and proposed Higgs field. (ML)
NASA Astrophysics Data System (ADS)
Geiger, Benjamin; Urbina, Juan-Diego; Hummel, Quirin; Richter, Klaus
2017-08-01
We present a semiclassical study of the spectrum of a few-body system consisting of two short-range interacting bosonic particles in one dimension, a particular case of a general class of integrable many-body systems where the energy spectrum is given by the solution of algebraic transcendental equations. By an exact mapping between δ -potentials and boundary conditions on the few-body wave functions, we are able to extend previous semiclassical results for single-particle systems with mixed boundary conditions to the two-body problem. The semiclassical approach allows us to derive explicit analytical results for the smooth part of the two-body density of states that are in excellent agreement with numerical calculations. It further enables us to include the effect of bound states in the attractive case. Remarkably, for the particular case of two particles in one dimension, the discrete energy levels obtained through a requantization condition of the smooth density of states are essentially in perfect agreement with the exact ones.
Multi-Mode Lamb Wave Arrival Time Extraction for Improved Tomographic Reconstruction
Hinders, Mark K.; Hou Jidong; Leonard, Kevin R.
2005-04-09
An ultrasonic signal processing technique is applied to multi-mode arrival time estimation from Lamb waveforms. The basic tool is a simplified time-scale projection called a dynamic wavelet fingerprint (DWFP) which enables direct observation of the variation of features of interest in non-stationary ultrasonic signals. The DWFP technique was used to automatically detect and evaluate each candidate through-transmitted Lamb mode. The area of the dynamic wavelet fingerprint was then used as a feature to distinguish false modes caused by noise and other interference from the true modes of interest. The set of estimated arrival times were then used as inputs for tomographic reconstruction. The Lamb wave tomography images generated with these estimated arrival times were able to indicate different defects in aluminum plates.
Multi-mode sliding mode control for precision linear stage based on fixed or floating stator.
Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei
2016-02-01
This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.
Research on optical fiber magnetic field sensors based on multi-mode fiber and spherical structure
NASA Astrophysics Data System (ADS)
Wang, Yan; Tong, Zheng-rong; Zhang, Wei-hua; Luan, Pan-pan; Zhao, Yue; Xue, Li-fang
2017-01-01
A magnetic field sensor with a magnetic fluid (MF)-coated intermodal interferometer is proposed and experimentally demonstrated. The interferometer is formed by sandwiching a segment of single mode fiber (SMF) between a segment of multi-mode fiber (MMF) and a spherical structure. It can be considered as a cascade of the traditional SMF-MMF-SMF structure and MMF-SMF-sphere structure. The transmission spectral characteristics change with the variation of applied magnetic field. The experimental results exhibit that the magnetic field sensitivities for wavelength and transmission loss are 0.047 nm/mT and 0.215 dB/mT for the interference dip around 1 535.36 nm. For the interference dip around 1548.41nm, the sensitivities are 0.077 nm/mT and 0.243 dB/mT. Simultaneous measurement can be realized according to the different spectral responses.
Note: Coupling of multiple laser diodes into a multi-mode fiber.
Ivonyak, Y; Piechal, B; Mrozowicz, M; Bercha, A; Trzeciakowski, W
2014-03-01
Diode lasers are coupled to a multi-mode fiber (with 100-400 μm core) using a reflector in the form of a regular pyramid. The optimization of the optical setup allows to couple 60%-90% of light into the fiber. The demonstrator achieves 3.5 W in the 100/125 μm fiber with 8 violet (405 nm) diodes, 5.5 W in the 100/125 μm fiber with 8 blue (445 nm) diodes, and 3.3 W in the 200/250 μm fiber with red (638 nm) diodes. The device can work with lasers emitting at many different wavelengths, including green (532 nm) frequency-doubled lasers. Our work was motivated by potential medical applications of these laser sources.
Dhote, Sharvari Zu, Jean; Zhu, Yang
2015-04-20
In this paper, a nonlinear wideband multi-mode piezoelectric vibration-based energy harvester (PVEH) is proposed based on a compliant orthoplanar spring (COPS), which has an advantage of providing multiple vibration modes at relatively low frequencies. The PVEH is made of a tri-leg COPS flexible structure, where three fixed-guided beams are capable of generating strong nonlinear oscillations under certain base excitation. A prototype harvester was fabricated and investigated through both finite-element analysis and experiments. The frequency response shows multiple resonance which corresponds to a hardening type of nonlinear resonance. By adding masses at different locations on the COPS structure, the first three vibration modes are brought close to each other, where the three hardening nonlinear resonances provide a wide bandwidth for the PVEH. The proposed PVEH has enhanced performance of the energy harvester in terms of a wide frequency bandwidth and a high-voltage output under base excitations.
Multi-mode sliding mode control for precision linear stage based on fixed or floating stator
NASA Astrophysics Data System (ADS)
Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei
2016-02-01
This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.
Laser Welding of Copper Using Multi Mode Fiber Lasers at Near Infrared Wavelength
NASA Astrophysics Data System (ADS)
Liebl, S.; Wiedenmann, R.; Ganser, A.; Schmitz, P.; Zaeh, M. F.
Due to the increasing electrification of automotive drives and the expansion of decentralized renewable energygeneration, the consumption of copper for the fabrication of electrical components such as electric motors or conducting paths increases. To jointhese components, laser welding is more frequently used since it represents a flexible and fully automatable joining process. Because of the high thermal conductivity, the low absorption coefficient forinfrared wavelength of common laser beam sources and the resulting limited process efficiency, welding of copper alloys represents a major challenge for laser assisted processes. In this paper, experimental investigationsare presented to identify arising process limits during laser welding of pure copper materials with multi-mode fiber lasers at near infrared wavelength depending on the applied laser power and welding velocity. In addition, a potential stabilization of the welding process by shielding gas support was examined. Further investigations were focused on the influence of shielding gas on the molten pool geometry.
Refractive index sensors based on the fused tapered special multi-mode fiber
NASA Astrophysics Data System (ADS)
Fu, Xing-hu; Xiu, Yan-li; Liu, Qin; Xie, Hai-yang; Yang, Chuan-qing; Zhang, Shun-yang; Fu, Guang-wei; Bi, Wei-hong
2016-01-01
In this paper, a novel refractive index (RI) sensor is proposed based on the fused tapered special multi-mode fiber (SMMF). Firstly, a section of SMMF is spliced between two single-mode fibers (SMFs). Then, the SMMF is processed by a fused tapering machine, and a tapered fiber structure is fabricated. Finally, a fused tapered SMMF sensor is obtained for measuring external RI. The RI sensing mechanism of tapered SMMF sensor is analyzed in detail. For different fused tapering lengths, the experimental results show that the RI sensitivity can be up to 444.517 81 nm/RIU in the RI range of 1.334 9—1.347 0. The RI sensitivity is increased with the increase of fused tapering length. Moreover, it has many advantages, including high sensitivity, compact structure, fast response and wide application range. So it can be used to measure the solution concentration in the fields of biochemistry, health care and food processing.
Decoherence of spin-deformed bosonic model
Dehdashti, Sh.; Mahdifar, A.; Bagheri Harouni, M.; Roknizadeh, R.
2013-07-15
The decoherence rate and some parameters affecting it are investigated for the generalized spin-boson model. We consider the spin-bosonic model when the bosonic environment is modeled by the deformed harmonic oscillators. We show that the state of the environment approaches a non-linear coherent state. Then, we obtain the decoherence rate of a two-level system which is in contact with a deformed bosonic environment which is either in thermal equilibrium or in the ground state. By using some recent realization of f-deformed oscillators, we show that some physical parameters strongly affect the decoherence rate of a two-level system. -- Highlights: •Decoherence of the generalized spin-boson model is considered. •In this model the environment consists of f-oscillators. •Via the interaction, the state of the environment approaches non-linear coherent states. •Effective parameters on decoherence are considered.
A multi-mode shock tube for investigation of blast-induced traumatic brain injury.
Reneer, Dexter V; Hisel, Richard D; Hoffman, Joshua M; Kryscio, Richard J; Lusk, Braden T; Geddes, James W
2011-01-01
Blast-induced mild traumatic brain injury (bTBI) has become increasingly common in recent military conflicts. The mechanisms by which non-impact blast exposure results in bTBI are incompletely understood. Current small animal bTBI models predominantly utilize compressed air-driven membrane rupture as their blast wave source, while large animal models use chemical explosives. The pressure-time signature of each blast mode is unique, making it difficult to evaluate the contributions of the different components of the blast wave to bTBI when using a single blast source. We utilized a multi-mode shock tube, the McMillan blast device, capable of utilizing compressed air- and compressed helium-driven membrane rupture, and the explosives oxyhydrogen and cyclotrimethylenetrinitramine (RDX, the primary component of C-4 plastic explosives) as the driving source. At similar maximal blast overpressures, the positive pressure phase of compressed air-driven blasts was longer, and the positive impulse was greater, than those observed for shockwaves produced by other driving sources. Helium-driven shockwaves more closely resembled RDX blasts, but by displacing air created a hypoxic environment within the shock tube. Pressure-time traces from oxyhydrogen-driven shockwaves were very similar those produced by RDX, although they resulted in elevated carbon monoxide levels due to combustion of the polyethylene bag used to contain the gases within the shock tube prior to detonation. Rats exposed to compressed air-driven blasts had more pronounced vascular damage than those exposed to oxyhydrogen-driven blasts of the same peak overpressure, indicating that differences in blast wave characteristics other than peak overpressure may influence the extent of bTBI. Use of this multi-mode shock tube in small animal models will enable comparison of the extent of brain injury with the pressure-time signature produced using each blast mode, facilitating evaluation of the blast wave components
LLNL Measurements of Graded-Index Multi-Mode Fiber (ITF 47)
Saito, T.T.
2000-05-01
The Russian Federal Nuclear Center-All Russian Research Institute of Technical Physics, located in the Nuclear City of Snezhinsk, east of the Ural mountains and the Lawrence Livermore National Laboratories have been investigating the possibility of establishing a commercial optical fiber manufacturing facility. These discussions began in the summer of 1998. At that time three samples (single mode and multi-mode) of optical fiber were left at the Sandia National Laboratory. Sandia measured two of the segments and sent them to LLNL. The optical loss at 1550 nm and 1300 nm were higher than commercially available fiber. The measurements were complicated because the geometry of the fibers also did not meet specification. Since the core was not adequately centered coupling of optical energy into the fiber being tested varied widely depending on which end of the fiber was used for insertion. The results of these measurements were summarized in the informal report dated June 11, 1999, which was hand carried by Dr. Paul Herman during his July 1999 visit. During the July visit a 1.2-km long section of graded-index multimode fiber, ITF 47, was given to Herman. We had requested samples longer than the earlier ones (which were {approx}0.1 km long) in order that a cutback method could be used for the transmission measurements. The optical loss using the cutback technique and the transmission spectral measurements in the 600-1700 mn region are reported. Also physical measurements are reported of the fiber's diameter, concentricity, ellipticity and tensile strength (proof test). The test results are summarized in Table 1, ''Comparative Data for Multi-mode Optical Fiber.'' The table includes the values from the Industrial specification TIA/EIA 402AAAB, the commercial specification for Corning's 50/125 CPC6, the values measured on ITF-47 and provided by C-70, and LLNL's values for ITF-47 as well as the multimode values from the June 1999 samples.
Multi-Mode transport modeling of the International Thermonuclear Experimental Reactor (ITER)
Bateman, G.; Kritz, A.H.; Kinsey, J.E.; Redd, A.J.
1998-06-01
Predictions are made for the performance of the International Thermonuclear Experimental Reactor (ITER) [R. Aymar, V. Chuyanov, M. Huguet, R. Parker, and Y. Shimomura, in {ital Proceedings of the Sixteenth International Atomic Energy Agency Fusion Energy Conference, Montr{acute e}al, Canada 1996} (International Atomic Energy Agency, Vienna, 1997), Paper IAEA-CN-64/01-1] design using the Multi-Mode model in the time-dependent one- and one-half-dimensional (1-1/2-D) BALDUR [C. E. Singer {ital et al.}, Comput. Phys. Commun. {bold 49}, 275 (1988)] transport code. This model predicts the temperature and density profiles observed in present-day tokamak experiments more closely on the average than other models currently available. Simulations using the Multi-Mode transport model, with its inherent gyro-Bohm scaling, indicate that ITER will ignite, even with edge temperatures as low as 0.25 keV (L-mode, or low-confinement mode, boundary conditions) or with volume averaged density as low as 0.775{times}10{sup 20}m{sup {minus}3} (just below the Greenwald density limit, when T{sub edge}=0.75keV). The ignition is found to be thermally stable, and the fusion power production is easily controlled by varying plasma density, impurity content, or edge temperatures. The nonequilibrium impurity radiation model used in these simulations predicts that a significant fraction of the fusion power is radiated when conditions are close to marginal ignition. {copyright} {ital 1998 American Institute of Physics.}
A Multi-Mode Shock Tube for Investigation of Blast-Induced Traumatic Brain Injury
Reneer, Dexter V.; Hisel, Richard D.; Hoffman, Joshua M.; Kryscio, Richard J.; Lusk, Braden T.
2011-01-01
Abstract Blast-induced mild traumatic brain injury (bTBI) has become increasingly common in recent military conflicts. The mechanisms by which non-impact blast exposure results in bTBI are incompletely understood. Current small animal bTBI models predominantly utilize compressed air-driven membrane rupture as their blast wave source, while large animal models use chemical explosives. The pressure-time signature of each blast mode is unique, making it difficult to evaluate the contributions of the different components of the blast wave to bTBI when using a single blast source. We utilized a multi-mode shock tube, the McMillan blast device, capable of utilizing compressed air- and compressed helium-driven membrane rupture, and the explosives oxyhydrogen and cyclotrimethylenetrinitramine (RDX, the primary component of C-4 plastic explosives) as the driving source. At similar maximal blast overpressures, the positive pressure phase of compressed air-driven blasts was longer, and the positive impulse was greater, than those observed for shockwaves produced by other driving sources. Helium-driven shockwaves more closely resembled RDX blasts, but by displacing air created a hypoxic environment within the shock tube. Pressure-time traces from oxyhydrogen-driven shockwaves were very similar those produced by RDX, although they resulted in elevated carbon monoxide levels due to combustion of the polyethylene bag used to contain the gases within the shock tube prior to detonation. Rats exposed to compressed air-driven blasts had more pronounced vascular damage than those exposed to oxyhydrogen-driven blasts of the same peak overpressure, indicating that differences in blast wave characteristics other than peak overpressure may influence the extent of bTBI. Use of this multi-mode shock tube in small animal models will enable comparison of the extent of brain injury with the pressure-time signature produced using each blast mode, facilitating evaluation of the blast wave
Borlase, Anna; Rudge, James W.
2017-01-01
Multi-host infectious agents challenge our abilities to understand, predict and manage disease dynamics. Within this, many infectious agents are also able to use, simultaneously or sequentially, multiple modes of transmission. Furthermore, the relative importance of different host species and modes can itself be dynamic, with potential for switches and shifts in host range and/or transmission mode in response to changing selective pressures, such as those imposed by disease control interventions. The epidemiology of such multi-host, multi-mode infectious agents thereby can involve a multi-faceted community of definitive and intermediate/secondary hosts or vectors, often together with infectious stages in the environment, all of which may represent potential targets, as well as specific challenges, particularly where disease elimination is proposed. Here, we explore, focusing on examples from both human and animal pathogen systems, why and how we should aim to disentangle and quantify the relative importance of multi-host multi-mode infectious agent transmission dynamics under contrasting conditions, and ultimately, how this can be used to help achieve efficient and effective disease control. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289259
Supersymmetric Ito equation: Bosonization and exact solutions
Ren Bo; Yu Jun; Lin Ji
2013-04-15
Based on the bosonization approach, the N=1 supersymmetric Ito (sIto) system is changed to a system of coupled bosonic equations. The approach can effectively avoid difficulties caused by intractable fermionic fields which are anticommuting. By solving the coupled bosonic equations, the traveling wave solutions of the sIto system are obtained with the mapping and deformation method. Some novel types of exact solutions for the supersymmetric system are constructed with the solutions and symmetries of the usual Ito equation. In the meanwhile, the similarity reduction solutions of the model are also studied with the Lie point symmetry theory.
Exact diagonalization of non-Hermitian so(3,2) models: Generalized two-mode boson systems
NASA Astrophysics Data System (ADS)
Zhang, Hong-Biao; Wang, Gangcheng
2016-12-01
We propose a unified approach to exactly diagonalize generalized non-Hermitian so(3,2) models. This approach is a series of similarity transformations, which is constructed by some similarity transformation operators associated with su(1,1) and su(2) subalgebras of so(3,2) Lie algebra. During this diagonalization, it is worth noting that a key step is to get rid of the terms E ˆ ± and F ˆ ± together via the proper similarity transformations first. In this way, exact solutions of the non-Hermitian so(3,2) models are obtained. Meanwhile we give the corresponding eigenstates, which are regarded as Lie algebra so(3,2) coherent-like number states. The results can cover the generic form of the eigenvalues and eigenstates to the generalized non-Hermitian two-mode boson systems with the discrete spectrum, including 2D PT-symmetric and non-PT-symmetric oscillators as the special cases. Also they are true for the Hermitian case.
Thermostatistics of bosonic and fermionic Fibonacci oscillators
NASA Astrophysics Data System (ADS)
Algin, Abdullah; Arik, Metin; Senay, Mustafa; Topcu, Gozde
2017-01-01
In this work, we first introduce some new properties concerning the Fibonacci calculus. We then discuss the thermostatistics of gas models of two-parameter deformed oscillators, called bosonic and fermionic Fibonacci oscillators, in the thermodynamical limit. In this framework, we analyze the behavior of two-parameter deformed mean occupation numbers describing the Fibonacci-type bosonic and fermionic intermediate-statistics particles. A virial expansion of the equation of state for the bosonic Fibonacci oscillators’ gas model is obtained in both two and three dimensions, and the first five virial coefficients are derived in terms of the real independent deformation parameters p and q. The effect of bosonic and fermionic p, q-deformation on the thermostatistical properties of Fibonacci-type p, q-boson and p, q-fermion gas models are also discussed. The results obtained in this work can be useful for investigating some exotic quasiparticle states encountered in condensed matter systems.
Self-imaging and high-beam-quality operation in multi-mode planar waveguide optical amplifiers.
Baker, Howard; Lee, Jason; Hall, Denis
2002-03-25
Self-imaging in a multi-mode active waveguide is examined as a method to preserve beam quality when amplifying a fundamental gaussian beam. Misalignment tolerance, gain saturation and thermal lensing effects are evaluated for the use of self-imaging in high average power, diodepumped, planar waveguide lasers.
Lincoln, Don
2016-11-16
The Higgs boson burst into the public arena on July 4, 2012, when scientists working at the CERN laboratory announced the particle’s discovery. However the initial discovery was a bit tentative, with the need to verify that the discovered particle was, indeed, the Higgs boson. In this video, Fermilab’s Dr. Don Lincoln looks at the data from the perspective of 2016 and shows that more recent analyses further supports the idea that the Higgs boson is what was discovered.
Does Sequence Matter in Multi-Mode Surveys: Results from an Experiment
Wagner, James; Arrieta, Jennifer; Guyer, Heidi; Ofstedal, Mary Beth
2014-01-01
Interest in a multi-mode approach to surveys has grown substantially in recent years, in part due to increased costs of face-to-face interviewing and the emergence of the internet as a survey mode. Yet, there is little systematic evidence of the impact of a multimode approach on survey costs and errors. This paper reports the results of an experiment designed to evaluate whether a mixed-mode approach to a large screening survey would produce comparable response rates at a lower cost than a face-to-face screening effort. The experiment was carried out in the Health and Retirement Study (HRS), an ongoing panel study of Americans over age 50. In 2010, HRS conducted a household screening survey to recruit new sample members to supplement the existing sample. The experiment varied the sequence of modes with which the screening interview was delivered. One treatment offered mail first, followed by face-to-face interviewing; the other started with face-to-face and then mail. A control group was offered only face-to-face interviewing. Results suggest that the mixed mode options reduced costs without reducing response rates to the screening interview. There is some evidence, however, that the sequence of modes offered may impact the response rate for a follow-up in-depth interview PMID:24764767
Characterisation of multi-mode propagation in silicon nitride slab waveguides
NASA Astrophysics Data System (ADS)
Jennings, B. D.; McCloskey, D.; Gough, J. J.; Hoang, T.; Abadía, N.; Zhong, C.; Karademir, E.; Bradley, A. L.; Donegan, J. F.
2017-01-01
A simple experimental method for determining the number of modes in planar dielectric multi-mode waveguides, and the effective index difference of these modes, is presented. Applying a thin, dye-doped polymer cladding, the fluorescence excited by multiple modes propagating in a silicon nitride slab waveguide is imaged to extract information. Interference between the modes produces a structured intensity profile along the waveguide which is constant in time. The spatial frequencies of this intensity profile are directly linked to the propagation constants of the underlying modes. Through a discrete Fourier transform, the modes’ effective index differences are found and compare well with analytically calculated values. Furthermore, the amplitudes in the Fourier transform are directly related to the power in each mode. Comparing the amplitudes of the Fourier components as a function of propagation distance, an estimate of the propagation losses of the individual modes relative to one another is made. The method discussed could be applied to analysing mode behaviour in integrated photonic devices, most notably in mode-division multiplexing.
Refractive index sensor based on multi-mode plastic optical fiber with long period grating
NASA Astrophysics Data System (ADS)
Teng, Chuanxin; Yu, Fangda; Ding, Yue; Zheng, Jie
2017-05-01
A multi-mode plastic optical fiber (POF) with a long period grating (LPG) was proposed for a refractive index (RI) sensing probe. The LPG was fabricated on the surface of the POF by a simple die-press-print method using a commercial available thread rod as the mould. The RI sensing performances for straight and U-shaped POFs with LPGs were studied. It is found that the straight RI sensing probe with LPG structure was not sensitive enough for RI measurement. After bending the straight POF probes with LPGs into U-shaped probes, the RI sensing performance was improved markedly. By altering the structural parameters, the RI sensing performances of the U-shaped POF probes with LPGs were optimized, a sensitivity of 1130%/RIU with a resolution of 8.44×10-4 in the RI range of 1.33-1.41 was obtained. The probe is a low cost solution for RI sensing purpose, which has the features of simple structure, easy fabrication, compact size and intensity modulation at visible wavelengths.
Tidal deformability of compact boson stars
NASA Astrophysics Data System (ADS)
Sennett, Noah; Steinhoff, Jan; Hinderer, Tanja; Buonanno, Alessandra
2017-01-01
Gravitational waves can be used to probe the structure of compact objects in coalescing binary systems. This structure enters the pre-merger waveform through tidal interactions between the two bodies, characterized by each object's tidal deformability. We investigate whether these effects can differentiate binary black holes from systems containing compact boson stars. We compute the tidal deformability for various boson star models, including ultracompact non-topological solitonic solutions.
NASA Astrophysics Data System (ADS)
Osipov, Vladimir Al.; Kanzieper, Eugene
2007-08-01
Motivated by the ongoing discussion about a seeming asymmetry in the performance of fermionic and bosonic replicas, we present an exact, nonperturbative approach to both fermionic and bosonic zero-dimensional replica field theories belonging to the broadly interpreted β=2 Dyson symmetry class. We then utilize the formalism developed to demonstrate that the bosonic replicas do correctly reproduce the microscopic spectral density in the QCD-inspired chiral Gaussian unitary ensemble. This disproves the myth that the bosonic replica field theories are intrinsically faulty.
Single scale cluster expansions with applications to many Boson and unbounded spin systems
NASA Astrophysics Data System (ADS)
Lohmann, Martin
2015-06-01
We develop a cluster expansion to show exponential decay of correlations for quite general single scale spin systems, as they arise in lattice quantum field theory and discretized functional integral representations for observables of quantum statistical mechanics. We apply our results to the small field approximation to the coherent state correlation functions of the grand canonical Bose gas at negative chemical potential, constructed by Balaban et al. [Ann. Henri Poincaré 11, 151-350 (2010c)], and to N component unbounded spin systems with repulsive two body interaction and massive, possibly complex, covariance. Our cluster expansion is derived by a single application of the Brydges-Kennedy-Abdesselam-Rivasseau interpolation formula.
Single scale cluster expansions with applications to many Boson and unbounded spin systems
Lohmann, Martin
2015-06-15
We develop a cluster expansion to show exponential decay of correlations for quite general single scale spin systems, as they arise in lattice quantum field theory and discretized functional integral representations for observables of quantum statistical mechanics. We apply our results to the small field approximation to the coherent state correlation functions of the grand canonical Bose gas at negative chemical potential, constructed by Balaban et al. [Ann. Henri Poincaré 11, 151–350 (2010c)], and to N component unbounded spin systems with repulsive two body interaction and massive, possibly complex, covariance. Our cluster expansion is derived by a single application of the Brydges-Kennedy-Abdesselam-Rivasseau interpolation formula.
Exceptional point and degeneracy of the neutral Higgs boson system H-A
Felix-Beltran, O.; Gomez-Bock, M.; Hernandez, E.; Mondragon, A.; Mondragon, M.
2009-04-20
We analyze the masses and mixings of the isolated neutral and heavy Higgs fields H and A of the Minimal Supersymmetric Standard Model (MSSM) with CP violation, which have opposite CP parities and nearly degenerate masses. At the degeneracy point, the hypersurfaces that represent the physical masses as functions of the system parameters have a rank one algebraic branch point, and the real and imaginary parts have branch cuts, both starting at the same exceptional point but extending in opposite directions in parameter space. Associated with this singularity, the propagator for the mixed neutral Higgs system H-A has a double pole in the non-physical sheet of the squared energy complex plane s. The continuity of the transition amplitude matrix at the exact degeneracy of the masses is examined.
Composite bosons in bilayer ν=1 system: An application of the Murthy-Shankar formalism
NASA Astrophysics Data System (ADS)
Stanić, Ivan; Milovanović, Milica V.
2005-01-01
We calculate the dispersion of the out-of-phase mode characteristic for the bilayer ν=1 quantum Hall system applying the version of Chern-Simons theory of Murthy and Shankar that cures the unwanted bare electron mass dependence in the low-energy description of quantum Hall systems. The obtained value for the mode when d , distance between the layers, is zero is in a good agreement with the existing pseudospin picture of the system. For d nonzero but small we find that the mode is linearly dispersing and its velocity to a good approximation depends linearly on d . This is in agreement with the Hartree-Fock calculations of the pseudospin picture that predicts a linear dependence on d , and contrary to the naive Hartree predictions with dependence on the square root of d . We set up a formalism that enables one to consider fluctuations around the found stationary point values. In addition we address the case of imbalanced layers in the Murthy-Shankar formalism.
Robust boson dispenser: Quantum state preparation in interacting many-particle systems
NASA Astrophysics Data System (ADS)
Reshodko, Irina; Benseny, Albert; Busch, Thomas
2017-08-01
We present a technique to control the spatial state of a small cloud of interacting particles at low temperatures with almost perfect fidelity using spatial adiabatic passage. To achieve this, the resonant trap energies of the system are engineered in such a way that a single, well-defined eigenstate connects the initial and desired states and is isolated from the rest of the spectrum. We apply this procedure to the task of separating a small pre-defined number of particles (up to 10) from an initial cloud and show that it can be implemented in radio-frequency traps using experimentally realistic parameters.
Majorization preservation of Gaussian bosonic channels
NASA Astrophysics Data System (ADS)
Jabbour, Michael G.; García-Patrón, Raúl; Cerf, Nicolas J.
2016-07-01
It is shown that phase-insensitive Gaussian bosonic channels are majorization-preserving over the set of passive states of the harmonic oscillator. This means that comparable passive states under majorization are transformed into equally comparable passive states by any phase-insensitive Gaussian bosonic channel. Our proof relies on a new preorder relation called Fock-majorization, which coincides with regular majorization for passive states but also induces another order relation in terms of mean boson number, thereby connecting the concepts of energy and disorder of a quantum state. The consequences of majorization preservation are discussed in the context of the broadcast communication capacity of Gaussian bosonic channels. Because most of our results are independent of the specific nature of the system under investigation, they could be generalized to other quantum systems and Hamiltonians, providing a new tool that may prove useful in quantum information theory and especially quantum thermodynamics.
Comparison of single-/few-/multi-mode 850 nm VCSELs for optical OFDM transmission.
Kao, Hsuan-Yun; Tsai, Cheng-Ting; Leong, Shan-Fong; Peng, Chun-Yen; Chi, Yu-Chieh; Huang, Jian Jang; Kuo, Hao-Chung; Shih, Tien-Tsorng; Jou, Jau-Ji; Cheng, Wood-Hi; Wu, Chao-Hsin; Lin, Gong-Ru
2017-07-10
For high-speed optical OFDM transmission applications, a comprehensive comparison of the homemade multi-/few-/single-transverse mode (MM/FM/SM) vertical cavity surface emitting laser (VCSEL) chips is performed. With microwave probe, the direct encoding of pre-leveled 16-QAM OFDM data and transmission over 100-m-long OM4 multi-mode-fiber (MMF) are demonstrated for intra-datacenter applications. The MM VCSEL chip with the largest emission aperture of 11 μm reveals the highest differential quantum efficiency which provides the highest optical power of 8.67 mW but exhibits the lowest encodable bandwidth of 21 GHz. In contrast, the SM VCSEL chip fabricated with the smallest emission aperture of only 3 μm provides the highest 3-dB encoding bandwidth up to 23 GHz at a cost of slight heat accumulation. After optimization, with the trade-off set between the receiving signal-to-noise ratio (SNR) and bandwidth, the FM VCSEL chip guarantees the highest optical OFDM transmission bit rate of 96 Gbit/s under back-to-back case with its strongest throughput. Among three VCSEL chips, the SM VCSEL chip with nearly modal-dispersion free feature is treated as the best candidate for carrying the pre-leveled 16-QAM OFDM data over 100-m OM4-MMF with same material structure but exhibits different oxide-layer confined gain cross-sections with one another at 80-Gbit/s with the smallest receiving power penalty of 1.77 dB.
LLNL Measurements of Graded-Index Multi-Mode Optical Fiber (ITF 47)
NASA Astrophysics Data System (ADS)
Saito, T. T.
2000-05-01
The Russian Federal Nuclear Center-All Russian Research Institute of Technical Physics, located in the Nuclear City of Snezhinsk, east of the Ural mountains and the Lawrence Livermore National Laboratories have been investigating the possibility of establishing a commercial optical fiber manufacturing facility. These discussions began in the summer of 1998. At that time three samples (single mode and multi-mode) of optical fiber were left at the Sandia National Laboratory. Sandia measured two of the segments and sent them to LLNL. The optical loss at 1550 nm and 1300 nm were higher than commercially available fiber. The measurements were complicated because the geometry of the fibers also did not meet specification. Since the core was not adequately centered coupling of optical energy into the fiber being tested varied widely depending on which end of the fiber was used for insertion. The results of these measurements were summarized in the informal report dated June 11, 1999, which was hand carried by Dr. Paul Herman during his July 1999 visit. During the July visit a 1.2-km long section of graded-index multimode fiber, ITF 47, was given to Herman. We had requested samples longer than the earlier ones (which were (approx) 0.1 km long) in order that a cutback method could be used for the transmission measurements. The optical loss using the cutback technique and the transmission spectral measurements in the 600-1700 mn region are reported. Also physical measurements are reported of the fiber's diameter, concentricity, ellipticity and tensile strength (proof test).
MULTI-MODE ERROR FIELD CORRECTION ON THE DIII-D TOKAMAK
SCOVILLE, JT; LAHAYE, RJ
2002-10-01
OAK A271 MULTI-MODE ERROR FIELD CORRECTION ON THE DIII-D TOKAMAK. Error field optimization on DIII-D tokamak plasma discharges has routinely been done for the last ten years with the use of the external ''n = 1 coil'' or the ''C-coil''. The optimum level of correction coil current is determined by the ability to avoid the locked mode instability and access previously unstable parameter space at low densities. The locked mode typically has toroidal and poloidal mode numbers n = 1 and m = 2, respectively, and it is this component that initially determined the correction coil current and phase. Realization of the importance of nearby n = 1 mode components m = 1 and m = 3 has led to a revision of the error field correction algorithm. Viscous and toroidal mode coupling effects suggested the need for additional terms in the expression for the radial ''penetration'' field B{sub pen} that can induce a locked mode. To incorporate these effects, the low density locked mode threshold database was expanded. A database of discharges at various toroidal fields, plasma currents, and safety factors was supplement4ed with data from an experiment in which the fields of the n = 1 coil and C-coil were combined, allowing the poloidal mode spectrum of the error field to be varied. A multivariate regression analysis of this new low density locked mode database was done to determine the low density locked mode threshold scaling relationship n{sub e} {proportional_to} B{sub T}{sup -0.01} q{sub 95}{sup -0.79} B{sub pen} and the coefficients of the poloidal mode components in the expression for B{sub pen}. Improved plasma performance is achieved by optimizing B{sub pen} by varying the applied correction coil currents.
Boson shells harboring charged black holes
Kleihaus, Burkhard; Kunz, Jutta; Laemmerzahl, Claus; List, Meike
2010-11-15
We consider boson shells in scalar electrodynamics coupled to Einstein gravity. The interior of the shells can be empty space, or harbor a black hole or a naked singularity. We analyze the properties of these types of solutions and determine their domains of existence. We investigate the energy conditions and present mass formulae for the composite black hole-boson shell systems. We demonstrate that these types of solutions violate black hole uniqueness.
Evolution of boson-fermion stars
NASA Astrophysics Data System (ADS)
Valdez-Alvarado, Susana; Palenzuela, Carlos; Alic, Daniela; Ureña-López, L. Arturo; Becerril, Ricardo
2012-08-01
The boson-fermion stars can be modeled with a complex scalar field coupled minimally to a perfect fluid (i.e., without viscosity and non-dissipative). We present a study of these solutions and their dynamical evolution by solving numerically the Einstein-Klein-Gordon-Hydrodynamic (EKGHD) system. It is shown that stable configurations exist, but stability of general configurations depends finely upon the number of bosons and fermions.
Minimally symmetric Higgs boson
Low, Ian
2015-06-17
Models addressing the naturalness of a light Higgs boson typically employ symmetries, either bosonic or fermionic, to stabilize the Higgs mass. We consider a setup with the minimal amount of symmetries: four shift symmetries acting on the four components of the Higgs doublet, subject to the constraints of linearly realized SU(2)(L) x U(1)(Y) electroweak symmetry. Up to terms that explicitly violate the shift symmetries, the effective Lagrangian can be derived, irrespective of the spontaneously broken group G in the ultraviolet, and is universal among all models where the Higgs arises as a pseudo-Nambu-Goldstone boson. Very high energy scatterings of vector bosons could provide smoking gun signals of a minimally symmetric Higgs boson.
Hybrid UWB and WiMAX radio-over-multi-mode fibre for in-building optical networks
NASA Astrophysics Data System (ADS)
Perez, J.; Llorente, R.
2014-01-01
In this paper the use of hybrid WiMedia-defined ultra-wideband (UWB) and IEEE 802.16d WiMAX radio-over-fibre is proposed and experimentally demonstrated for multi-mode based in-building optical networks with the advantage of great immunity to optical transmission impairments. In the proposed approach, spectral coexistence of both signals must be achieved with negligible mutual interference. The experimental study performed addressed an indoor configuration with 50 μm multi-mode fibres (MMF) and 850 nm vertical-cavity surface-emitting laser (VCSEL) transmitters. The results indicate that the impact of the wireless convergence in radio-over-multi-mode fibre (RoMMF) is significant for UWB transmissions, mainly due to MMF dispersion and electrooptical (EO) devices with limited bandwidth. On the other hand, WiMAX transmission is feasible for a 300 m MMF and 30 m wireless link in the presence of UWB, with -31 dBm WiMAX EVM.
Supersymmetric Higgs Bosons in Weak Boson Fusion
Hollik, Wolfgang; Plehn, Tilman; Rauch, Michael; Rzehak, Heidi
2009-03-06
We compute the complete supersymmetric next-to-leading-order corrections to the production of a light Higgs boson in weak-boson fusion. The size of the electroweak corrections is of similar order as the next-to-leading-order corrections in the standard model. The supersymmetric QCD corrections turn out to be significantly smaller than expected and than their electroweak counterparts. These corrections are an important ingredient to a precision analysis of the (supersymmetric) Higgs sector at the LHC, either as a known correction factor or as a contribution to the theory error.
Hwang, Jungseek
2016-03-31
We introduce an approximate method which can be used to simulate the optical conductivity data of correlated multiband systems for normal and superconducting cases by taking advantage of a reversed process in comparison to a usual optical data analysis, which has been used to extract the electron-boson spectral density function from measured optical spectra of single-band systems, like cuprates. We applied this method to optical conductivity data of two multiband pnictide systems (Ba0.6K0.4Fe2As2 and LiFeAs) and obtained the electron-boson spectral density functions. The obtained electron-boson spectral density consists of a sharp mode and a broad background. The obtained spectral density functions of the multiband systems show similar properties as those of cuprates in several aspects. We expect that our method helps to reveal the nature of strong correlations in the multiband pnictide superconductors.
NASA Astrophysics Data System (ADS)
Panas, Jaromir; Kauch, Anna; Byczuk, Krzysztof
2017-03-01
We use the Bose-Hubbard model with an effective infinite-range interaction to describe the correlated lattice bosons in an optical cavity. We study both static and spectral properties of such system within the bosonic dynamical mean-field theory, which is the state-of-the-art method for strongly correlated bosonic systems. Both similarities and differences are found and discussed between our results and those obtained within different theoretical methods and experiment.
Fermion boson metamorphosis in field theory
Ha, Y.K.
1982-01-01
In two-dimensional field theories many features are especially transparent if the Fermi fields are represented by non-local expressions of the Bose fields. Such a procedure is known as boson representation. Bilinear quantities appear in the Lagrangian of a fermion theory transform, however, as simple local expressions of the bosons so that the resulting theory may be written as a theory of bosons. Conversely, a theory of bosons may be transformed into an equivalent theory of fermions. Together they provide a basis for generating many interesting equivalences between theories of different types. In the present work a consistent scheme for constructing a canonical Fermi field in terms of a real scalar field is developed and such a procedure is valid and consistent with the tenets of quantum field theory is verified. A boson formulation offers a unifying theme in understanding the structure of many theories. This is illustrated by the boson formulation of a multifermion theory with chiral and internal symmetries. The nature of dynamical generation of mass when the theory undergoes boson transmutation and the preservation of continuous chiral symmetry in the massive case are examined. The dynamics of the system depends to a great extent on the specific number of fermions and different models of the same system can have very different properties. Many unusual symmetries of the fermion theory, such as hidden symmetry, duality and triality symmetries, are only manifest in the boson formulation. The underlying connections between some models with U(N) internal symmetry and another class of fermion models built with Majorana fermions which have O(2N) internal symmetry are uncovered.
Heavy fermion behavior explained by bosons
NASA Technical Reports Server (NTRS)
Kallio, A.; Poykko, S.; Apaja, V.
1995-01-01
Conventional heavy fermion (HF) theories require existence of massive fermions. We show that heavy fermion phenomena can also be simply explained by existence of bosons with moderate mass but temperature dependent concentration below the formation temperature T(sub B), which in turn is close to room temperature. The bosons B(++) are proposed to be in chemical equilibrium with a system of holes h(+): B(++) = h(+) + h(+). This equilibrium is governed by a boson breaking function f(T), which determines the decreasing boson density and the increasing fermion density with increasing temperature. Since HF-compounds are hybridized from minimum two elements, we assume in addition existence of another fermion component h(sub s)(+) with temperature independent density. This spectator component is thought to be the main agent in binding the bosons in analogy with electronic or muonic molecules. Using a linear boson breaking function we can explain temperature dependence of the giant linear specific heat coefficient gamma(T) coming essentially from bosons. The maxima in resistivity, Hall coefficient, and susceptibility are explained by boson localization effects due to the Wigner crystallization. The antiferromagnetic transitions in turn are explained by similar localization of the pairing fermion system when their density n(sub h)(T(sub FL)) becomes lower than n(sub WC), the critical density of Wigner crystallization. The model applies irrespective whether a compound is superconducting or not. The same model explains the occurrence of low temperature antiferromagnetism also in high-T(sub c) superconductors. The double transition in UPt3 is proposed to be due to the transition of the pairing fermion liquid from spin polarized to unpolarized state.
Bonding effectiveness of a new 'multi-mode' adhesive to enamel and dentine.
Hanabusa, Masao; Mine, Atsushi; Kuboki, Takuo; Momoi, Yasuko; Van Ende, Annelies; Van Meerbeek, Bart; De Munck, Jan
2012-06-01
Self-etch adhesives are well adopted in general practice, obviously primarily thanks to their ease of use and fast application time. Nevertheless, phosphoric acid is still often recommended to beforehand etch enamel following a so-called 'selective' enamel-etch technique, this in particular when most cavity margins end in enamel. The purpose of this study was to test if a new one-step adhesive can be applied in a multi-mode manner, this following different, either 'full' or 'selective', self-etch and etch-and-rinse approaches. Specific research hypotheses tested were that prior phosphoric-acid etching did not affect the bonding effectiveness of the one-step adhesive to enamel and dentine, and that the bonding effectiveness to dentine was also not affected when the adhesive was applied either following a 'dry-bonding' or 'wet-bonding' etch-and-rinse technique. The micro-tensile bond strength (μTBS) of the one-step self-etch adhesive G-Bond Plus (GC, Tokyo, Japan; 1-SEA) was measured when it was bonded to bur-cut enamel following either a 'self-etch' or an 'etch-and-rinse' adhesive protocol, and to bur-cut dentine when applied following either a 'self-etch', a 'dry-bonding' or a 'wet-bonding' etch-and-rinse adhesive protocol. Bond-strength testing was corroborated by ultra-structural analysis of the interfacial interaction at enamel and dentine using transmission electron microscopy (TEM). Prior phosphoric-acid etching significantly increased the bonding effectiveness of the 1-SEA to enamel. A clearly enhanced micro-retentive surface was revealed by TEM. To dentine, no statistically significant difference in bonding effectiveness was recorded when the 1-SEA was either applied following a self-etch or both etch-and-rinse approaches. The 'dry-bonding' etch-and-rinse protocol was significantly more effective than its 'wet-bonding' version. TEM however revealed indications of low-quality hybridisation following both etch-and-rinse approaches, in particular in the form
Lincoln, Don
2016-12-14
The Higgs boson burst into the public arena on July 4, 2012, when scientists working at the CERN laboratory announced the particleâs discovery. However the initial discovery was a bit tentative, with the need to verify that the discovered particle was, indeed, the Higgs boson. In this video, Fermilabâs Dr. Don Lincoln looks at the data from the perspective of 2016 and shows that more recent analyses further supports the idea that the Higgs boson is what was discovered.
Experimental scattershot boson sampling
Bentivegna, Marco; Spagnolo, Nicolò; Vitelli, Chiara; Flamini, Fulvio; Viggianiello, Niko; Latmiral, Ludovico; Mataloni, Paolo; Brod, Daniel J.; Galvão, Ernesto F.; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto; Sciarrino, Fabio
2015-01-01
Boson sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialized quantum computer. Current experimental schemes, however, are still insufficient for a convincing demonstration of the advantage of quantum over classical computation. A new variation of this task, scattershot boson sampling, leads to an exponential increase in speed of the quantum device, using a larger number of photon sources based on parametric down-conversion. This is achieved by having multiple heralded single photons being sent, shot by shot, into different random input ports of the interferometer. We report the first scattershot boson sampling experiments, where six different photon-pair sources are coupled to integrated photonic circuits. We use recently proposed statistical tools to analyze our experimental data, providing strong evidence that our photonic quantum simulator works as expected. This approach represents an important leap toward a convincing experimental demonstration of the quantum computational supremacy. PMID:26601164
Ryoo, Eon Na; Ha, Eun Ho; Cho, Jin Young
2013-04-01
Simulation-based learning has become a powerful method to improve the quality of care and help students meet the challenges of increasingly complex clinical practice settings. The purpose of this study was to identify the learning effects using high-fidelity SimMan and multi-mode simulation. Participants in this study were 38 students who were enrolled in an intensive course for a major in nursing at R college. Collected data were analyzed using Chi-square, t-test, and independent t-test with the SPSS 18.0 for Windows Program. There were no statistically significant differences in learning effects between high-fidelity SimMan and multi-mode simulation group. However, skills in clinical performance in the high-fidelity SimMan group were higher than in the multi-mode group (p=.014), communication in clinical performance in multi-mode simulation group was higher than in the high-fidelity SimMan group (p<.001). Multi-mode simulation with a standardized patient is an effective learning method in many ways compared to a high-fidelity simulator. These results suggest that multi-mode simulation be offered to students in nursing colleges which cannot afford to purchase a high-fidelity simulator, or offered as an alternative.
Beyond the Schwinger boson representation of the su(2)-algebra
NASA Astrophysics Data System (ADS)
Tsue, Yasuhiko; Providência, Constança; da Providência, João; Yamamura, Masatoshi
2015-04-01
With the use of two kinds of boson operators, a new boson representation of the su(2)-algebra is proposed. The basic idea comes from the pseudo su(1,1)-algebra recently given by the present authors [Y. Tsue et al., Prog. Theor. Exp. Phys. 2013, 103D04 (2013)]. It forms a striking contrast to the Schwinger boson representation of the su(2)-algebra, which is also based on two kinds of bosons. It is proved that this new boson representation obeys the su(2)-algebra in a certain subspace in the whole boson space constructed by the Schwinger boson representation of the su(1,1)-algebra. This representation may be suitable for describing the time dependence of the system interacting with the external environment in the framework of the thermo field dynamics formalism, i.e., phase space doubling. Further, several deformations related to the su(2)-algebra in this boson representation are discussed. On the basis of these deformed algebras, various types of time evolution of a simple boson system are investigated.
Ultra-thin rigid endoscope: two-photon imaging through a graded-index multi-mode fiber.
Sivankutty, Siddharth; Andresen, Esben Ravn; Cossart, Rosa; Bouwmans, Géraud; Monneret, Serge; Rigneault, Hervé
2016-01-25
Rigid endoscopes like graded-index (GRIN) lenses are known tools in biological imaging, but it is conceptually difficult to miniaturize them. In this letter, we demonstrate an ultra-thin rigid endoscope with a diameter of only 125 μm. In addition, we identify a domain where two-photon endoscopic imaging with fs-pulse excitation is possible. We validate the ultra-thin rigid endoscope consisting of a few cm of graded-index multi-mode fiber by using it to acquire optically sectioned two-photon fluorescence endoscopic images of three-dimensional samples.
NASA Astrophysics Data System (ADS)
Li, Biaobin; Lu, Yalin; He, Zhigang; Li, Weiwei; Jia, Qika; Wang, Lin
2017-02-01
The cylindrical dielectric loaded waveguide (DLW) supports a discrete set of modes, which can be excited by electron beam passing through the structure, and the high-order modes can be the harmonics of the fundamental one by properly choosing the parameters of the DLW. By using a train of electron bunches, repeated at the fundamental frequency of the DLW, as the driving source, coherent and simultaneous excitation of multi-modes can be expected. With this proposed scheme, multi-color narrow-band THz radiation with high pulse power and high frequency can be obtained simultaneously.
Bosonic self-energy functional theory
NASA Astrophysics Data System (ADS)
Hügel, Dario; Werner, Philipp; Pollet, Lode; Strand, Hugo U. R.
2016-11-01
We derive the self-energy functional theory for bosonic lattice systems with broken U(1) symmetry by parametrizing the bosonic Baym-Kadanoff effective action in terms of one- and two-point self-energies. The formalism goes beyond other approximate methods such as the pseudoparticle variational cluster approximation, the cluster composite boson mapping, and the Bogoliubov+U theory. It simplifies to bosonic dynamical-mean-field theory when constraining to local fields, whereas when neglecting kinetic contributions of noncondensed bosons, it reduces to the static mean-field approximation. To benchmark the theory, we study the Bose-Hubbard model on the two- and three-dimensional cubic lattice, comparing with exact results from path integral quantum Monte Carlo. We also study the frustrated square lattice with next-nearest-neighbor hopping, which is beyond the reach of Monte Carlo simulations. A reference system comprising a single bosonic state, corresponding to three variational parameters, is sufficient to quantitatively describe phase boundaries and thermodynamical observables, while qualitatively capturing the spectral functions, as well as the enhancement of kinetic fluctuations in the frustrated case. On the basis of these findings, we propose self-energy functional theory as the omnibus framework for treating bosonic lattice models, in particular, in cases where path integral quantum Monte Carlo methods suffer from severe sign problems (e.g., in the presence of nontrivial gauge fields or frustration). Self-energy functional theory enables the construction of diagrammatically sound approximations that are quantitatively precise and controlled in the number of optimization parameters but nevertheless remain computable by modest means.
Pan, Minghao; Yang, Yongmin; Guan, Fengjiao; Hu, Haifeng; Xu, Hailong
2017-01-01
The accurate monitoring of blade vibration under operating conditions is essential in turbo-machinery testing. Blade tip timing (BTT) is a promising non-contact technique for the measurement of blade vibrations. However, the BTT sampling data are inherently under-sampled and contaminated with several measurement uncertainties. How to recover frequency spectra of blade vibrations though processing these under-sampled biased signals is a bottleneck problem. A novel method of BTT signal processing for alleviating measurement uncertainties in recovery of multi-mode blade vibration frequency spectrum is proposed in this paper. The method can be divided into four phases. First, a single measurement vector model is built by exploiting that the blade vibration signals are sparse in frequency spectra. Secondly, the uniqueness of the nonnegative sparse solution is studied to achieve the vibration frequency spectrum. Thirdly, typical sources of BTT measurement uncertainties are quantitatively analyzed. Finally, an improved vibration frequency spectra recovery method is proposed to get a guaranteed level of sparse solution when measurement results are biased. Simulations and experiments are performed to prove the feasibility of the proposed method. The most outstanding advantage is that this method can prevent the recovered multi-mode vibration spectra from being affected by BTT measurement uncertainties without increasing the probe number. PMID:28758952
NASA Astrophysics Data System (ADS)
Kotwal, Ashutosh V.
2016-10-01
The measurement of the W boson mass has been growing in importance as its precision has improved, along with the precision of other electroweak observables and the top quark mass. Over the last decade, the measurement of the W boson mass has been led at hadron colliders. Combined with the precise measurement of the top quark mass at hadron colliders, the W boson mass helped to pin down the mass of the Standard Model Higgs boson through its induced radiative correction on the W boson mass. With the discovery of the Higgs boson and the measurement of its mass, the electroweak sector of the Standard Model is over-constrained. Increasing the precision of the W boson mass probes new physics at the TeV-scale. We summarize an extensive Tevatron (1984-2011) program to measure the W boson mass at the CDF and Dø experiments. We highlight the recent Tevatron measurements and prospects for the final Tevatron measurements.
Quantum simulation with a boson sampling circuit
NASA Astrophysics Data System (ADS)
González Olivares, Diego; Peropadre, Borja; Aspuru-Guzik, Alán; García-Ripoll, Juan José
2016-08-01
In this work we study a system that consists of 2 M matter qubits that interact through a boson sampling circuit, i.e., an M -port interferometer, embedded in two different architectures. We prove that, under the conditions required to derive a master equation, the qubits evolve according to effective bipartite X Y spin Hamiltonians, with or without local and collective dissipation terms. This opens the door to the simulation of any bipartite spin or hard-core boson models and exploring dissipative phase transitions as the competition between coherent and incoherent exchange of excitations. We also show that in the purely dissipative regime this model has a large number of exact and approximate dark states, whose structure and decay rates can be estimated analytically. We finally argue that this system may be used for the adiabatic preparation of boson sampling states encoded in the matter qubits.
NASA Astrophysics Data System (ADS)
Tsekov, R.
2017-04-01
Thermodynamically, bosons and fermions differ by their statistics only. A general entropy functional is proposed by superposition of entropic terms, typical for different quantum gases. The statistical properties of the corresponding Janus particles are derived by variation of the weight of the boson/fermion fraction. It is shown that di-bosons and anti-fermions separate in gas and liquid phases, while three-phase equilibrium appears for poly-boson/fermion Janus particles.
Dawson, S.; Haber, H.E.; Rindani, S.D.
1989-05-01
This is the summary report of the Higgs Boson Working Group. We discuss a variety of search techniques for a Higgs boson which is lighter than the Z. The processes K /yields/ /pi/H, /eta//prime/ /yields/ /eta/H,/Upsilon/ /yields/ H/gamma/ and e/sup +/e/sup /minus// /yields/ ZH are examined with particular attention paid to theoretical uncertainties in the calculations. We also briefly examine new features of Higgs phenomenology in a model which contains Higgs triplets as well as the usual doublet of scalar fields. 33 refs., 6 figs., 1 tab.
NASA Astrophysics Data System (ADS)
Holdom, B.
2014-07-01
We suggest that the Higgs boson is a light composite state that does not emerge from TeV scale strong dynamics for any generic reason, such as when it is pseudo-Goldstone boson. Instead, a state that is Higgs-like and fairly decoupled from heavier states may simply be a reflection of very particular strong dynamics, with properties quite distinct from more familiar large-Nc type gauge dynamics. We elaborate on this picture in the context of a strongly interacting fourth family and an effective 4-Higgs-doublet model. The origin of a decoupling limit and the corrections to it are discussed.
Simulating spin-boson models with matrix product states
NASA Astrophysics Data System (ADS)
Wall, Michael; Safavi-Naini, Arghavan; Rey, Ana Maria
2016-05-01
The global coupling of few-level quantum systems (``spins'') to a discrete set of bosonic modes is a key ingredient for many applications in quantum science, including large-scale entanglement generation, quantum simulation of the dynamics of long-range interacting spin models, and hybrid platforms for force and spin sensing. In many situations, the bosons are integrated out, leading to effective long-range interactions between the spins; however, strong spin-boson coupling invalidates this approach, and spin-boson entanglement degrades the fidelity of quantum simulation of spin models. We present a general numerical method for treating the out-of-equilibrium dynamics of spin-boson systems based on matrix product states. While most efficient for weak coupling or small numbers of boson modes, our method applies for any spatial and operator dependence of the spin-boson coupling. In addition, our approach allows straightforward computation of many quantities of interest, such as the full counting statistics of collective spin measurements and quantum simulation infidelity due to spin-boson entanglement. We apply our method to ongoing trapped ion quantum simulator experiments in analytically intractable regimes. This work is supported by JILA-NSF-PFC-1125844, NSF-PIF- 1211914, ARO, AFOSR, AFOSR-MURI, and the NRC.
Probing the spin-parity of the Higgs boson via jet kinematics in vector boson fusion
NASA Astrophysics Data System (ADS)
Djouadi, A.; Godbole, R. M.; Mellado, B.; Mohan, K.
2013-06-01
Determining the spin and the parity quantum numbers of the recently discovered Higgs-like boson at the LHC is a matter of great importance. In this Letter, we consider the possibility of using the kinematics of the tagging jets in Higgs production via the vector boson fusion (VBF) process to test the tensor structure of the Higgs-vector boson (HVV) interaction and to determine the spin and CP properties of the observed resonance. We show that an anomalous HVV vertex, in particular its explicit momentum dependence, drastically affects the rapidity between the two scattered quarks and their transverse momenta and, hence, the acceptance of the kinematical cuts that allow to select the VBF topology. The sensitivity of these observables to different spin-parity assignments, including the dependence on the LHC center of mass energy, are evaluated. In addition, we show that in associated Higgs production with a vector boson some kinematical variables, such as the invariant mass of the system and the transverse momenta of the two bosons and their separation in rapidity, are also sensitive to the spin-parity assignments of the Higgs-like boson.
Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios; Alameh, Kamal
2013-12-16
In this paper, a high-speed reconfigurable card-to-card optical interconnect architecture based on hybrid free-space and multi-mode fiber (MMF) propagation is proposed. The use of free-space signal transmission provides flexibility and reconfigurability and the MMF extends the achievable interconnection range. A printed-circuit-board (PCB) based integrated optical interconnect module is designed and developed and proof-of-concept demonstration experiments are carried out. Results show that 3 × 10 Gb/s reconfigurable optical interconnect is realized with ~12 cm free-space propagation and a 10 m MMF length. In addition, since air turbulence due to high temperature of electronic components and heat dissipation fans always exists in typical interconnect environments and it normally results in system performance degradation, its impact on the proposed reconfigurable optical interconnect scheme is also experimentally investigated. Results indicate that even with comparatively strong air turbulence, 3 × 10 Gb/s optical interconnects with flexibility can still be achieved and the power penalty is <0.7 dB.
NASA Astrophysics Data System (ADS)
Chen, Miawjane; Yan, Shangyao; Wang, Sin-Siang; Liu, Chiu-Lan
2015-02-01
An effective project schedule is essential for enterprises to increase their efficiency of project execution, to maximize profit, and to minimize wastage of resources. Heuristic algorithms have been developed to efficiently solve the complicated multi-mode resource-constrained project scheduling problem with discounted cash flows (MRCPSPDCF) that characterize real problems. However, the solutions obtained in past studies have been approximate and are difficult to evaluate in terms of optimality. In this study, a generalized network flow model, embedded in a time-precedence network, is proposed to formulate the MRCPSPDCF with the payment at activity completion times. Mathematically, the model is formulated as an integer network flow problem with side constraints, which can be efficiently solved for optimality, using existing mathematical programming software. To evaluate the model performance, numerical tests are performed. The test results indicate that the model could be a useful planning tool for project scheduling in the real world.
NASA Astrophysics Data System (ADS)
Mejia-Alvarez, Ricardo; Wilson, Brandon; Prestridge, Kathy; Extreme Fluids Team
2013-11-01
To support validation of RANS and LES codes for single-interface Richtmyer-Meshkov mixing, the Extreme Fluids Team at Los Alamos National Laboratory commissioned a Vertical Shock Tube. This facility has the capability of generating statistically stationary single- and multi-mode spatial perturbations on the fluid interface prior to shock-interface interaction. The present study focuses on comparing the evolution of shock-driven mixing under two different spatial perturbation conditions after interacting with a M = 1.2 shock wave. High resolution simultaneous PIV and PLIF are used for capturing 2D instantaneous realizations of velocity and density at different stages of the evolving interface. Multiple realizations of the flow at each one of these evolution stages are obtained to characterize the flow statistically. Also, a modal analysis via Singular Value Decomposition is performed on the density and velocity fields to elucidate the role of initial flow scales content on the transition to turbulent mixing.
Yang, Hua; Yang, Mingqi; Morrissey, Padraic E; Lu, Dan; Pan, Bi Wei; Zhao, Lingjuan; Corbett, Brian; Peters, Frank H
2016-03-21
A 1x2 multi-mode-interferometer (MMI) laser diode was successfully designed and fabricated, which demonstrated three coherent outputs of tunable single frequency emission with more than 30dB side mode suppression ratio (SMSR), a tuning range of 25nm in C and L band, as well as 750 kHz linewidth. This 1x2 MMI laser could be expanded to more advanced configurations such as 1xN or MxN (M≥1, N>2) MMI lasers to achieve a multiple coherent output source. In addition, these lasers do not require material regrowth and high resolution gratings which can significantly increase the yield and reduce the cost.
NASA Astrophysics Data System (ADS)
Yoshizawa, K.
2014-10-01
A new radially anisotropic shear wave speed model for the Australasian region is constructed from multi-mode phase dispersion of Love and Rayleigh waves. An automated waveform fitting technique based on a global optimization with the Neighbourhood Algorithm allows the exploitation of large numbers of three-component broad-band seismograms to extract path-specific dispersion curves covering the entire continent. A 3-D shear wave model is constructed including radial anisotropy from a set of multi-mode phase speed maps for both Love and Rayleigh waves. These maps are derived from an iterative inversion scheme incorporating the effects of ray-path bending due to lateral heterogeneity, as well as the finite frequency of the surface waves for each mode. The new S wave speed model exhibits major tectonic features of this region that are in good agreement with earlier shear wave models derived primarily from Rayleigh waves. The lateral variations of depth and thickness of the lithosphere-asthenosphere transition (LAT) are estimated from the isotropic (Voigt average) S wave speed model and its vertical gradient, which reveals correlations between the lateral variations of the LAT and radial anisotropy. The thickness of the LAT is very large beneath the Archean cratons in western Australia, whereas that in south Australia is thinner. The radial anisotropy model shows faster SH wave speed than SV beneath eastern Australia and the Coral Sea at the lithospheric depth. The faster SH anomaly in the lithosphere is also seen in the suture zone between the three cratonic blocks of Australia. One of the most conspicuous features of fast SH anisotropy is found in the asthenosphere beneath the central Australia, suggesting anisotropy induced by shear flow in the asthenosphere beneath the fast drifting Australian continent.
Development of the multi-mode horn-lens configuration for the LSPE-SWIPE B-mode experiment
NASA Astrophysics Data System (ADS)
Legg, Stephen; Lamagna, Luca; Coppi, Gabriele; de Bernardis, Paolo; Giuliani, Grazia; Gualtieri, Riccardo; Marchetti, Tommaso; Masi, Silvia; Pisano, Giampaolo; Maffei, Bruno
2016-07-01
The Large Scale Polarisation Explorer (LSPE) is a balloon-borne experiment aiming to measure the B-mode component of the CMB polarisation at large angular scales. Onboard LSPE, the Short Wavelength Instrument for the Polarisation Explorer (SWIPE) is a bolometric polarimeter observing in three bands centred at 140, 220 and 240 GHz. The telescope is a single large-diameter plano-convex lens with a cold aperture stop. A small number of multi-mode feed horns feeding bolometric detectors are used within the focal plane, achieving a sensitivity equivalent to that of 100's of single-mode horns. Simulations have been performed to predict the multi-mode optical response of the horn-lens configuration for centre and off-axis pixels pertaining to each frequency band. The horn has been simulated to a high accuracy using the Method of Moments. Using the horn simulation result as a source, the optical response of the lens has been examined using the more approximate simulation technique; Ray-Launching Geometrical Optics (RL-GO). Solution accuracy and simulation time depend heavily on the choice of RL-GO simulation parameters including: mesh size; the number of launched rays; and how densely the horn source beam is sampled. Individual convergence studies have been performed for each of these parameters and a final model has been obtained as a compromise between simulation time and accuracy. The instrumental polarisation of the lens is predicted to be at the -50 dB level. Finally, the optimal location of where to place the telescope focus in relation to the horn to maximise on-axis gain has been investigated. Several techniques agreed that the `phase centre' is around 20 mm behind the horn aperture at 140 GHz, increasing to 30 mm at 220 and 240 GHz. Taking into account beam truncation effects caused by the finite size of the telescope was found to reduce the overall variation in on-axis gain.
Influence of the quantum interference on the bosonic and fermionic ion-ion collisions
NASA Astrophysics Data System (ADS)
Hong, Woo-Pyo; Jung, Young-Dae
2014-03-01
The quantum interference effects on the bosonic-bosonic (He-4)-(He-4), fermionic-fermionic (He-3)-(He-3), and bosonic-fermionic (He-4)-(He-3) ion-ion collisions are investigated by using the isotope of the He nucleus in dense semiclassical Coulomb systems with the Faxen-Holtzmark method. It is found that the scattering cross section for the fermionic-fermionic ion-ion collision is greater than the bosonic-bosonic and bosonic-fermionic ion collision cross sections. It is also found that the collisional induced quantum interference effect enhances the ion-ion collision cross section in semiclassical Coulomb systems. The variation of the quantum-mechanical effect on the bosonic and fermionic ion-ion collisions is also discussed. This paper is dedicated to the late Prof. P. K. Shukla in memory of exciting and stimulating collaborations on physical processes in semiclassical Coulomb systems.
Bosonization Theorem and a Model of High-Tc Superconductor.
NASA Astrophysics Data System (ADS)
Ren, Hai-Cang
1996-03-01
For a purely fermionic system on a lattice, there exists a different, but well defined system on the same lattice, consisting both of bona fide fermions and bosons with an interaction depending on a parameter G characterizing on-site repulsion between particles(R. Friedberg, T. D. Lee and H. C. Ren, Phys. Rev. B50, 10190 (1994).). The energy spectrum and the scattering matrix of the former are identical to those in the finite-energy sector of the latter in the hard-core limit, G→∞. This theorem is particularly useful for the description of a fermionic system whose low-lying spectrum consists of bosonic resonances. We argue that the high-Tc superconductors belong to this category and the long-range order in the superphase can be identified with the condensation of resonance bosons. A short coherence length, results from μSR experiments, measurements of the Hall number and the anomalous behavior of H_c2 near T=0 can be understood in terms of this resonance-boson model(R. Friedberg, T. D. Lee and H. C. Ren, Phys. Rev. B42, 4122 (1990).). We have also examined the possibility of a bosonic d-wave resonance(O.Tchernyshyov, A.S.Blaer and H.Ren, in the current Proceedings.). In this case, the bosonization theorem predicts coexistence of an s-wave bosonic condensate and a d-wave gap parameter for fermions.
Simulating generic spin-boson models with matrix product states
NASA Astrophysics Data System (ADS)
Wall, Michael L.; Safavi-Naini, Arghavan; Rey, Ana Maria
2016-11-01
The global coupling of few-level quantum systems ("spins") to a discrete set of bosonic modes is a key ingredient for many applications in quantum science, including large-scale entanglement generation, quantum simulation of the dynamics of long-range interacting spin models, and hybrid platforms for force and spin sensing. We present a general numerical framework for treating the out-of-equilibrium dynamics of such models based on matrix product states. Our approach applies for generic spin-boson systems: it treats any spatial and operator dependence of the two-body spin-boson coupling and places no restrictions on relative energy scales. We show that the full counting statistics of collective spin measurements and infidelity of quantum simulation due to spin-boson entanglement, both of which are difficult to obtain by other techniques, are readily calculable in our approach. We benchmark our method using a recently developed exact solution for a particular spin-boson coupling relevant to trapped ion quantum simulators. Finally, we show how decoherence can be incorporated within our framework using the method of quantum trajectories, and study the dynamics of an open-system spin-boson model with spatially nonuniform spin-boson coupling relevant for trapped atomic ion crystals in the presence of molecular ion impurities.
NASA Astrophysics Data System (ADS)
David, André Dührssen, Michael
2016-10-01
This chapter presents an overview of the measured properties of the Higgs boson discovered in 2012 by the ATLAS and CMS collaborations at the CERN LHC. Searches for deviations from the properties predicted by the standard theory are also summarised. The present status corresponds to the combined analysis of the full Run 1 data sets of collisions collected at centre-of-mass energies of 7 and 8 TeV.
The Finite Horizon Optimal Multi-Modes Switching Problem: The Viscosity Solution Approach
El Asri, Brahim Hamadene, Said
2009-10-15
In this paper we show existence and uniqueness of a solution for a system of m variational partial differential inequalities with inter-connected obstacles. This system is the deterministic version of the Verification Theorem of the Markovian optimal m-states switching problem. The switching cost functions are arbitrary. This problem is in relation with the valuation of firms in a financial market.
NASA Astrophysics Data System (ADS)
Sin, Yongkun; Lingley, Zachary; Brodie, Miles; Presser, Nathan; Moss, Steven C.
2017-02-01
High-power single-mode (SM) and multi-mode (MM) InGaAs-AlGaAs strained quantum well (QW) lasers are critical components for both telecommunications and space satellite communications systems. However, little has been reported on failure modes and degradation mechanisms of high-power SM and MM InGaAs-AlGaAs strained QW lasers although it is crucial to understand failure modes and underlying degradation mechanisms in developing these lasers that meet lifetime requirements for space satellite systems, where extremely high reliability of these lasers is required. Our present study addresses the aforementioned issues by performing long-term life-tests followed by failure mode analysis (FMA) and physics of failure investigation. We performed long-term accelerated life-tests on state-of-the-art SM and MM InGaAs-AlGaAs strained QW lasers under ACC (automatic current control) mode. Our life-tests have accumulated over 25,000 test hours for SM lasers and over 35,000 test hours for MM lasers. FMA was performed on failed SM lasers using electron beam induced current (EBIC). This technique allowed us to identify failure types by observing dark line defects. All the SM failures we studied showed catastrophic and sudden degradation and all of these failures were bulk failures. Our group previously reported that bulk failure or COBD (catastrophic optical bulk damage) is the dominant failure mode of MM InGaAs-AlGaAs strained QW lasers. Since degradation mechanisms responsible for COBD are still not well understood, we also employed other techniques including focused ion beam (FIB) processing and high-resolution TEM to further study dark line defects and dislocations in post-aged lasers. Our long-term life-test results and FMA results are reported.
NASA Astrophysics Data System (ADS)
Sin, Yongkun; Lingley, Zachary; Brodie, Miles; Huang, Michael; Bushmaker, Adam; Theiss, Jesse; Presser, Nathan; Foran, Brendan; Moss, Steven C.
2016-03-01
Remarkable progress made in vertical cavity surface emitting lasers (VCSELs) emitting at 850 and 980 nm has led them to find an increasing number of applications in high speed data communications as well as in potential space satellite systems. However, little has been reported on reliability and failure modes of InGaAs VCSELs emitting at ~980 nm although it is crucial to understand failure modes and underlying degradation mechanisms in developing these VCSELs that exceed lifetime requirements for space missions. The active layer of commercial VCSELs that we studied consisted of two or three InGaAs quantum wells. The laser structures were fabricated into deep mesas followed by a steam oxidation process to form oxide-apertures for current and optical confinements. Our multi- mode VCSELs showed a laser threshold of ~ 0.5 mA at RT. Failures were generated via accelerated life-testing of VCSELs. For the present study, we report on failure mode analysis of degraded oxide-VCSELs using various techniques. We employed nondestructive techniques including electroluminescence (EL), optical beam induced current (OBIC), and electron beam induced current (EBIC) techniques as well as destructive techniques including focused ion beam (FIB) and high-resolution TEM techniques to study VCSELs that showed different degradation behaviors. Especially, we employed FIB systems to locally remove a portion of top-DBR mirrors of degraded VCSELs, which made it possible for our subsequent EBIC and OBIC techniques to locate damaged areas that were generated as a result of degradation processes and also for our HR-TEM technique to prepare TEM cross sections from damaged areas. Our nondestructive and destructive physical analysis results are reported including defect and structural analysis results from pre-aged VCSELs as well as from degraded VCSELs life-tested under different test conditions.
Influence of boson mass on chiral phase transition in QED3
NASA Astrophysics Data System (ADS)
Feng, Hong-tao; Wang, Xiu-Zhen; Yu, Xin-hua; Zong, Hong-shi
2016-08-01
Based on the truncated Dyson-Schwinger equations for the fermion propagator with N fermion flavors at zero temperature, the chiral phase transition of quantum electrodynamics in 2 +1 dimensions (QED3 ) with boson mass—which is obtained via the Anderson-Higgs mechanism—is investigated. In the chiral limit, we find that the critical behavior of QED3 with a massless boson is different from that with a massive boson: the chiral phase transition in the presence of a nonzero boson mass reveals the typical second-order phase transition, at either the critical boson mass or a critical number of fermion flavors, while for a vanishing boson mass it exhibits a higher than second-order phase transition at the critical number of fermion flavors. Furthermore, it is shown that the system undergoes a crossover behavior from a small number of fermion flavors or boson mass to its larger one beyond the chiral limit.
A Remark on the Ground State Energy of Bosonic Atoms
NASA Astrophysics Data System (ADS)
Hogreve, H.
2011-08-01
Monotonicity properties of the ground state energy of bosonic atoms as established in a recent paper by M.K.H. Kiessling [J. Stat. Phys. 139:1063 (2009)] are studied. Symmetry and scaling arguments lead to a more direct proof of a slightly stronger result of this monotonicity and the behavior of the ground state energy as a function of the number of bosonic electrons. Furthermore, invoking appropriate lower and upper bounds on two-electron systems, the stability of the bosonics He- ion is rigorously demonstrated.
Boson Stars with Vector Meson Exchange Repulsive Interaction
NASA Astrophysics Data System (ADS)
Fitrah, M.; Rangga Sakti, Alfian; Sulaksono, Anto
2016-08-01
Spherically symmetric static boson stars are solutions of the system of equations of Klein-Gordon equation which is coupled to the Einstein and Proca equation with complex scalar field with U(1) gauge symmetry. In this work, we do not solve these equations directly but first we solve simultaneous equations Klein-Gordon and Proca in flat space-time numerically to obtain interacting boson equation of state (EOS), then we ”boost” the corresponding EOS to curved space-time so that, we can solve Einstein equations. If we assume that the distribution of boson in boson stars is inhomogeneous, the boosted EOS is anisotropic in the sense that the pressure to the tangential direction is not the same as the one in the radial direction. We find numerically solutions to see the EOS which are formed in boson stars as the consequence of inhomogeneous assumption. We have found that there is no physically stable solution for inhomogeneous EOS. However, if we assume that the distribution of bosons in matter is homogeneous, we can get a stable solution for static boson stars.
Luong, J; Shellie, R A; Cortes, H; Gras, R; Hayward, T
2012-03-16
Steam condensate water treatment is a vital and integral part of the overall cooling water treatment process. Steam condensate often contains varying levels of carbon dioxide and oxygen which acts as an oxidizer. Carbon dioxide forms corrosive carbonic acid when dissolved in condensed steam. To neutralize the harmful effect of the carbonic acid, volatile amine compounds such as morpholine, cyclohexylamine, and diethylaminoethanol are often employed as part of a strategy to control corrosion in the water treatment process. Due to the high stability of these compounds in a water matrix, the indirect addition of such chemicals into the process via steam condensate often results in their presence throughout the process and even into the final product. It is therefore important to understand the impact of these chemicals and their fate within a chemical plant. The ability to analyze such compounds by gas chromatography has historically been difficult due to the lack of chromatographic system inertness at the trace level concentrations especially in an aqueous matrix. Here a highly sensitive, practical, and reliable gas chromatographic approach is described for the determination of morpholine, cyclohexylamine, and diethylaminoethanol in steam condensate at the part-per-billion (ppb) levels. The approach does not require any sample enrichment or derivatization. The technique employs a multi-mode inlet operating in pulsed splitless mode with programmed inlet temperature for sample introduction, an inert base-deactivated capillary column for solute separation and flame ionization detection. Chromatographic performance was further enhanced by the incorporation of 2-propanol as a co-solvent. Detection limits for morpholine, cyclohexylamine, diethylaminoethanol were established to be 100 ppb (v/v), with relative standard deviations (RSD) of less than 6% at the 95% confidence level (n=20) and a percent recovery of 96% or higher for the solutes of interest over a range of 0
NASA Astrophysics Data System (ADS)
Nan, Qi; Fan, Chen; Lingwei, Zhang; Xiaoman, Wang; Baoyong, Chi
2013-09-01
A reconfigurable multi-mode direct-conversion transmitter (TX) with integrated frequency synthesizer (FS) is presented. The TX as well as the FS is designed with a flexible architecture and frequency plan, which helps to support all the 433/868/915 MHz ISM band signals, with the reconfigurable bandwidth from 250 kHz to 2 MHz. In order to save power and chip area, only one 1.8 GHz VCO is adopted to cover the whole frequency range. All the operation modes can be regulated in real time by configuring the integrated register-bank through an SPI interface. Implemented in 180 nm CMOS, the FS achieves a frequency coverage of 320-460 MHz and 620-920 MHz. The lowest phase noise can be -107 dBc/Hz at a 100 kHz offset and -126 dBc/Hz at a 1 MHz offset. The transmitter features a + 10.2 dBm peak output power with a +9.5 dBm 1-dB-compression point and 250 kHz/500 kHz/1 MHz/2 MHz reconfigurable signal bandwidth.
NASA Astrophysics Data System (ADS)
Tjahyadi, H.; He, F.; Sammut, K.
2008-08-01
A hybrid multi-model-multi-mode adaptive resonant control (M4ARC) approach is proposed for dynamically loaded flexible beam structures to provide superior vibration damping performance as compared to its fixed-model and adaptive counterparts. The proposed approach uses a configurable controller, the parameters of which are updated using a fast and accurate on-line frequency identification method for N modes of interest. This method incorporates a simple supervision scheme that selects between the output of an N-mode filter bank (representing the multiple-fixed-model set) and the output of an estimator bank (representing the accurate model of the plant). The estimator bank comprises a multi-rate set of parallel N second-order recursive-least-squares estimators to achieve rapid parameter convergence. While the estimators are still in transition, the supervisor provides the configurable controller with an intermediate set of frequencies that correspond to the closest fixed model. Once the estimators converge, the supervisor selects the estimated frequency set to provide the configurable controller with an accurate representation of the current plant. This supervisor scheme significantly reduces the computational complexity as compared with existing counterparts. Experiments reveal that the proposed M4ARC approach offers the best compromise in terms of adapting to sudden and highly variable loading condition changes (within a bounded domain) while, at the same time, achieving fast transient performance.
NASA Astrophysics Data System (ADS)
Weber, F.; Distl, H.
2015-11-01
This paper derives an approximate collocated control solution for the mitigation of multi-mode cable vibration by semi-active damping with negative stiffness based on the control force characteristics of clipped linear quadratic regulator (LQR). The control parameters are derived from optimal modal viscous damping and corrected in order to guarantee that both the equivalent viscous damping coefficient and the equivalent stiffness coefficient of the semi-active cable damper force are equal to their desired counterparts. The collocated control solution with corrected control parameters is numerically validated by free decay tests of the first four cable modes and combinations of these modes. The results of the single-harmonic tests demonstrate that the novel approach yields 1.86 times more cable damping than optimal modal viscous damping and 1.87 to 2.33 times more damping compared to a passive oil damper whose viscous damper coefficient is optimally tuned to the targeted mode range of the first four modes. The improvement in case of the multi-harmonic vibration tests, i.e. when modes 1 and 3 and modes 2 and 4 are vibrating at the same time, is between 1.55 and 3.81. The results also show that these improvements are obtained almost independent of the cable anti-node amplitude. Thus, the proposed approximate real-time applicable collocated semi-active control solution which can be realized by magnetorheological dampers represents a promising tool for the efficient mitigation of stay cable vibrations.
NASA Astrophysics Data System (ADS)
O'Hagan, S.; Northern, J. H.; Gras, B.; Ewart, P.; Kim, C. S.; Kim, M.; Merritt, C. D.; Bewley, W. W.; Canedy, C. L.; Vurgaftman, I.; Meyer, J. R.
2016-06-01
The application of an interband cascade laser, ICL, to multi-mode absorption spectroscopy, MUMAS, in the mid-infrared region is reported. Measurements of individual mode linewidths of the ICL, derived from the pressure dependence of lineshapes in MUMAS signatures of single, isolated, lines in the spectrum of HCl, were found to be in the range 10-80 MHz. Multi-line spectra of methane were recorded using spectrally limited bandwidths, of approximate width 27 cm-1, defined by an interference filter, and consist of approximately 80 modes at spectral locations spanning the 100 cm-1 bandwidth of the ICL output. Calibration of the methane pressures derived from MUMAS data using a capacitance manometer provided measurements with an uncertainty of 1.1 %. Multi-species sensing is demonstrated by the simultaneous detection of methane, acetylene and formaldehyde in a gas mixture. Individual partial pressures of the three gases are derived from best fits of model MUMAS signatures to the data with an experimental error of 10 %. Using an ICL, with an inter-mode interval of ~10 GHz, MUMAS spectra were recorded at pressures in the range 1-10 mbar, and, based on the data, a potential minimum detection limit of the order of 100 ppmv is estimated for MUMAS at atmospheric pressure using an inter-mode interval of 80 GHz.
Park, Byoungchoo; Kim, Mi-Na; Kim, Sun Woong; Ho Park, Jin
2008-09-15
We studied 1-dimensional (1-D) photonic crystal (PC) films with three alternating layers to investigate multi-mode photonic band-gaps (PBGs) at red, green, and blue color regions. From simulations, it was shown that PCs with three alternating layered elements of [a/b/c] structure have sharp PBGs at the three color regions with the central wavelengths of 459 nm, 527 nm, and 626 nm, simultaneously. Experimentally, it was proven that red, green, and blue PBGs were generated clearly by the PCs, which were made of multilayers of [SiO(2)/Ta(2)O(5)/TiO(2)], based on the simulation. It was also shown that the measured wavelengths of the PBGs corresponded exactly to those of the simulated results. Moreover, it was demonstrated that a 1-D PC of [a/b/c] structure can be used for making white organic light emitting devices (OLEDs) with improved color rendering index (CRI) for color display or lighting.
Summing Planar Bosonic Open Strings
Bardakci, Korkut
2006-02-16
In earlier work, planar graphs of massless {phi}{sup 3} theory were summed with the help of the light cone world sheet picture and the mean field approximation. In the present article, the same methods are applied to the problem of summing planar bosonic open strings. They find that in the ground state of the system, string boundaries form a condensate on the world sheet, and a new string emerges from this summation. Its slope is always greater than the initial slope, and it remains non-zero even when the initial slope is set equal to zero. If they assume the initial string tends to a field a theory in the zero slope limit, this result provides evidence for string formation in field theory.
Development of robust and multi-mode control of tearing in DIII-D
Welander, A. S.; La Haye, R.J.; Humphreys, D. A.; Kolemen, E.; Volpe, F.
2016-06-02
Neoclassical tearing modes (NTMs) are instabilities that can produce undesirable magnetic islands in tokamak plasmas. They can be stabilized by applying electron cyclotron current drive (ECCD) at the island. The NTM control system on DIII-D can now control multiple modes. Each of 6 mirrors that reflect ECCD beams into the plasma can be assigned to different surfaces in the plasma where NTMs are unstable. The control system then steers the mirrors to keep the beams aimed at the surfaces. The system routinely stabilizes one NTM preemptively and has now also been used to control two modes in the same discharge. With the “catch-and-subdue” function, ECCD-generating gyrotrons can be turned on when NTMs appear and off after suppression. Newly triggered NTMs can be promptly suppressed if mode onset is detected early and ECCD immediately applied. Early mode detection is achieved in this paper by spectral analysis of Mirnov probes with a band-pass filter for the expected mode frequency. Targeted surfaces are tracked by equilibrium reconstructions (that include measurements of the motional Stark effect). The ECCD position is tracked by ray-tracing using the TORBEAM code. Several techniques are being explored for fine-tuning alignment when NTMs occur. One method adjusts ECCD alignment in steps until the island decays fast enough. A second method sweeps the alignment to find the optimum. A third method pulses gyrotrons and uses electron cyclotron emission to compare where the resulting temperature pulses are relative to temperature fluctuations from a rotating NTM. NTM control in ITER is expected to use active profile regulation to maximize controllability, followed by repeated catch-and-subdue actions if modes are retriggered, in order to maintain island size below the disruptive threshold while maximizing confinement and fusion gain. Between events, real-time tracking will be performed to maintain alignment and readiness for subsequent catch-andsubdue actions. Methods
Development of robust and multi-mode control of tearing in DIII-D
Welander, A. S.; La Haye, R.J.; Humphreys, D. A.; ...
2016-06-02
Neoclassical tearing modes (NTMs) are instabilities that can produce undesirable magnetic islands in tokamak plasmas. They can be stabilized by applying electron cyclotron current drive (ECCD) at the island. The NTM control system on DIII-D can now control multiple modes. Each of 6 mirrors that reflect ECCD beams into the plasma can be assigned to different surfaces in the plasma where NTMs are unstable. The control system then steers the mirrors to keep the beams aimed at the surfaces. The system routinely stabilizes one NTM preemptively and has now also been used to control two modes in the same discharge.more » With the “catch-and-subdue” function, ECCD-generating gyrotrons can be turned on when NTMs appear and off after suppression. Newly triggered NTMs can be promptly suppressed if mode onset is detected early and ECCD immediately applied. Early mode detection is achieved in this paper by spectral analysis of Mirnov probes with a band-pass filter for the expected mode frequency. Targeted surfaces are tracked by equilibrium reconstructions (that include measurements of the motional Stark effect). The ECCD position is tracked by ray-tracing using the TORBEAM code. Several techniques are being explored for fine-tuning alignment when NTMs occur. One method adjusts ECCD alignment in steps until the island decays fast enough. A second method sweeps the alignment to find the optimum. A third method pulses gyrotrons and uses electron cyclotron emission to compare where the resulting temperature pulses are relative to temperature fluctuations from a rotating NTM. NTM control in ITER is expected to use active profile regulation to maximize controllability, followed by repeated catch-and-subdue actions if modes are retriggered, in order to maintain island size below the disruptive threshold while maximizing confinement and fusion gain. Between events, real-time tracking will be performed to maintain alignment and readiness for subsequent catch-andsubdue actions
Simulating Bosonic Baths with Error Bars
NASA Astrophysics Data System (ADS)
Woods, M. P.; Cramer, M.; Plenio, M. B.
2015-09-01
We derive rigorous truncation-error bounds for the spin-boson model and its generalizations to arbitrary quantum systems interacting with bosonic baths. For the numerical simulation of such baths, the truncation of both the number of modes and the local Hilbert-space dimensions is necessary. We derive superexponential Lieb-Robinson-type bounds on the error when restricting the bath to finitely many modes and show how the error introduced by truncating the local Hilbert spaces may be efficiently monitored numerically. In this way we give error bounds for approximating the infinite system by a finite-dimensional one. As a consequence, numerical simulations such as the time-evolving density with orthogonal polynomials algorithm (TEDOPA) now allow for the fully certified treatment of the system-environment interaction.
Multi-Mode GF-3 Satellite Image Geometric Accuracy Verification Using the RPC Model.
Wang, Taoyang; Zhang, Guo; Yu, Lei; Zhao, Ruishan; Deng, Mingjun; Xu, Kai
2017-09-01
The GaoFen-3 (GF-3) satellite is the first C-band multi-polarization synthetic aperture radar (SAR) imaging satellite with a resolution up to 1 m in China. It is also the only SAR satellite of the High-Resolution Earth Observation System designed for civilian use. There are 12 different imaging models to meet the needs of different industry users. However, to use SAR satellite images for related applications, they must possess high geometric accuracy. In order to verify the geometric accuracy achieved by the different modes of GF-3 images, we analyze the SAR geometric error source and perform geometric correction tests based on the RPC model with and without ground control points (GCPs) for five imaging modes. These include the spotlight (SL), ultra-fine strip (UFS), Fine Strip I (FSI), Full polarized Strip I (QPSI), and standard strip (SS) modes. Experimental results show that the check point residuals are large and consistent without GCPs, but the root mean square error of the independent checkpoints for the case of four corner control points is better than 1.5 pixels, achieving a similar level of geometric positioning accuracy to that of international satellites. We conclude that the GF-3 satellite can be used for high-accuracy geometric processing and related industry applications.
Developing parameters for multi-mode ambient air models including the nanometer mode
NASA Astrophysics Data System (ADS)
Tronville, Paolo; Rivers, Richard
2017-06-01
The particle count, surface and mass in an occupied space can be modeled when the HVAC system airflows are known, along with the particle-size distribution for outdoor air, internal generation rates as a function of particle size, and the efficiency as a function of particle size for filters present. Outdoor air particle-size distribution is rarely available, but measures of particle mass concentration, PM2.5 and PM10, are often available for building locations. Outdoor air aerosol size distributions are well modeled by sums of two or three log-normal distributions, with essentially all mass in two larger modes. Studies have also shown that some mode parameters are, in general, related by simple functions. This paper shows how these relationships can be combined with known characteristics of PM2.5 and PM10 samplers to create reasonable inclusive models of outdoor air aerosol-size distributions. This information plus knowledge of indoor particle generation allows calculation of aerosol mass in occupied spaces. Estimation of parameters of aerosol modes with sizes below100 nm and measurement of filter efficiencies in that range are described.
Multi-Mode GF-3 Satellite Image Geometric Accuracy Verification Using the RPC Model
Wang, Taoyang; Yu, Lei; Deng, Mingjun; Xu, Kai
2017-01-01
The GaoFen-3 (GF-3) satellite is the first C-band multi-polarization synthetic aperture radar (SAR) imaging satellite with a resolution up to 1 m in China. It is also the only SAR satellite of the High-Resolution Earth Observation System designed for civilian use. There are 12 different imaging models to meet the needs of different industry users. However, to use SAR satellite images for related applications, they must possess high geometric accuracy. In order to verify the geometric accuracy achieved by the different modes of GF-3 images, we analyze the SAR geometric error source and perform geometric correction tests based on the RPC model with and without ground control points (GCPs) for five imaging modes. These include the spotlight (SL), ultra-fine strip (UFS), Fine Strip I (FSI), Full polarized Strip I (QPSI), and standard strip (SS) modes. Experimental results show that the check point residuals are large and consistent without GCPs, but the root mean square error of the independent checkpoints for the case of four corner control points is better than 1.5 pixels, achieving a similar level of geometric positioning accuracy to that of international satellites. We conclude that the GF-3 satellite can be used for high-accuracy geometric processing and related industry applications. PMID:28862658
Vibrational dynamics and boson peak in a supercooled polydisperse liquid.
Abraham, Sneha Elizabeth; Bagchi, Biman
2010-03-01
Vibrational density of states (VDOS) in a supercooled polydisperse liquid is computed by diagonalizing the Hessian matrix evaluated at the potential energy minima for systems with different values of polydispersity. An increase in polydispersity leads to an increase in the relative population of localized high-frequency modes. At low frequencies, the density of states shows an excess compared to the Debye squared-frequency law, which has been identified with the boson peak. The height of the boson peak increases with polydispersity and shows a rather narrow sensitivity to changes in temperature. While the modes comprising the boson peak appear to be largely delocalized, there is a sharp drop in the participation ratio of the modes that exist just below the boson peak indicative of the quasilocalized nature of the low-frequency vibrations. Study of the difference spectrum at two different polydispersity reveals that the increase in the height of boson peak is due to a population shift from modes with frequencies above the maximum in the VDOS to that below the maximum, indicating an increase in the fraction of the unstable modes in the system. The latter is further supported by the facilitation of the observed dynamics by polydispersity. Since the strength of the liquid increases with polydispersity, the present result provides an evidence that the intensity of boson peak correlates positively with the strength of the liquid, as observed earlier in many experimental systems.
Work fluctuations in bosonic Josephson junctions
NASA Astrophysics Data System (ADS)
Lena, R. G.; Palma, G. M.; De Chiara, G.
2016-05-01
We calculate the first two moments and full probability distribution of the work performed on a system of bosonic particles in a two-mode Bose-Hubbard Hamiltonian when the self-interaction term is varied instantaneously or with a finite-time ramp. In the instantaneous case, we show how the irreversible work scales differently depending on whether the system is driven to the Josephson or Fock regime of the bosonic Josephson junction. In the finite-time case, we use optimal control techniques to substantially decrease the irreversible work to negligible values. Our analysis can be implemented in present-day experiments with ultracold atoms and we show how to relate the work statistics to that of the population imbalance of the two modes.
Mixtures of bosonic and fermionic atoms in optical lattices
Albus, Alexander; Illuminati, Fabrizio; Eisert, Jens
2003-08-01
We discuss the theory of mixtures of bosonic and fermionic atoms in periodic potentials at zero temperature. We derive a general Bose-Fermi Hubbard Hamiltonian in a one-dimensional optical lattice with a superimposed harmonic trapping potential. We study the conditions for linear stability of the mixture and derive a mean-field criterion for the onset of a bosonic superfluid transition. We investigate the ground-state properties of the mixture in the Gutzwiller formulation of mean-field theory, and present numerical studies of finite systems. The bosonic and fermionic density distributions and the onset of quantum phase transitions to demixing and to a bosonic Mott-insulator are studied as a function of the lattice potential strength. The existence is predicted of a disordered phase for mixtures loaded in very deep lattices. Such a disordered phase possessing many degenerate or quasidegenerate ground states is related to a breaking of the mirror symmetry in the lattice.
Bose-Einstein condensates of bosonic Thomson atoms
NASA Astrophysics Data System (ADS)
Schneider, Tobias; Blümel, Reinhold
1999-10-01
A system of charged particles in a harmonic trap is a realization of Thomson's raisin cake model. Therefore, we call it a Thomson atom. Bosonic, fermionic and mixed Thomson atoms exist. In this paper we focus on bosonic Thomson atoms in isotropic traps. Approximating the exact ground state by a condensate we investigate ground-state properties at temperature T = 0 using the Hartree-Fock theory for bosons. In order to assess the quality of our mean-field approach we compare the Hartree-Fock results for bosonic Thomson helium with an exact diagonalization. In contrast to the weakly interacting Bose gas (alkali vapours) mean-field calculations are reliable in the limit of large particle density. The Wigner regime (low particle density) is discussed.
NASA Astrophysics Data System (ADS)
Greschner, S.; Piraud, M.; Heidrich-Meisner, F.; McCulloch, I. P.; Schollwöck, U.; Vekua, T.
2016-12-01
We study the quantum phases of bosons with repulsive contact interactions on a two-leg ladder in the presence of a uniform Abelian gauge field. The model realizes many interesting states, including Meissner phases, vortex fluids, vortex lattices, charge density waves, and the biased-ladder phase. Our work focuses on the subset of these states that breaks a discrete symmetry. We use density matrix renormalization group simulations to demonstrate the existence of three vortex-lattice states at different vortex densities and we characterize the phase transitions from these phases into neighboring states. Furthermore, we provide an intuitive explanation of the chiral-current reversal effect that is tied to some of these vortex lattices. We also study a charge-density-wave state that exists at 1/4 particle filling at large interaction strengths and flux values close to half a flux quantum. By changing the system parameters, this state can transition into a completely gapped vortex-lattice Mott-insulating state. We elucidate the stability of these phases against nearest-neighbor interactions on the rungs of the ladder relevant for experimental realizations with a synthetic lattice dimension. A charge-density-wave state at 1/3 particle filling can be stabilized for flux values close to half a flux quantum and for very strong on-site interactions in the presence of strong repulsion on the rungs. Finally, we analytically describe the emergence of these phases in the low-density regime, and, in particular, we obtain the boundaries of the biased-ladder phase, i.e., the phase that features a density imbalance between the legs. We make contact with recent quantum-gas experiments that realized related models and discuss signatures of these quantum states in experimentally accessible observables.
Oscillation of boson star in Newtonian approximation
NASA Astrophysics Data System (ADS)
Jarwal, Bharti; Singh, S. Somorendro
2017-03-01
Boson star (BS) rotation is studied under Newtonian approximation. A Coulombian potential term is added as perturbation to the radial potential of the system without disturbing the angular momentum. The results of the stationary states of these ground state, first and second excited state are analyzed with the correction of Coulombian potential. It is found that the results with correction increased in the amplitude of oscillation of BS in comparison to potential without perturbation correction.
NASA Technical Reports Server (NTRS)
Neilson, Jeffrey M. (Inventor)
2002-01-01
A horn has an input aperture and an output aperture, and comprises a conductive inner surface formed by rotating a curve about a central axis. The curve comprises a first arc having an input aperture end and a transition end, and a second arc having a transition end and an output aperture end. When rotated about the central axis, the first arc input aperture end forms an input aperture, and the second arc output aperture end forms an output aperture. The curve is then optimized to provide a mode conversion which maximizes the power transfer of input energy to the Gaussian mode at the output aperture.
NASA Astrophysics Data System (ADS)
Park, Jaegyu; Kwack, Myung-Joon; Joo, Jiho; Kim, Gyungock
2017-08-01
We investigate the single-mode operation in a silicon arrayed multi-mode waveguide grating. By introducing a double-etched structure at the boundary of a star coupler with inverse-tapered waveguides (WGs), the suppression of the mode-coupling between adjacent arrayed multi-mode WGs, and the adiabatic optical mode conversion between a FPR (free propagation region) and arrayed WGs can be achieved with a reduced phase error of the arrayed WGs. The fabricated four-channel Si arrayed waveguide grating (AWG) demonstrates a good performance level, such as a low insertion loss of 0.61 dB (0.73 dB) and low adjacent crosstalk less than -31.3 dB (-32.2 dB) for transverse-electric (TE) (transverse-magnetic, TM) polarization, in the range of ˜1300 nm wavelength.
NASA Astrophysics Data System (ADS)
Lee, Myoung-Jae; Jung, Young-Dae
2017-09-01
The influence of collision-dominated electrons on multi-mode Hasegawa space-charge waves are investigated in a complex plasma containing streaming ions. The dispersion relation for the multi-mode Hasegawa space-charge wave propagating in a cylindrical waveguide filled with dusty plasma containing collision-dominated electrons and streaming ions is derived by using the fluid equations and Poisson’s equation which lead to a Bessel equation. By the boundary condition, the roots of the Bessel function would characterize the property of space-charge wave propagation. It is found that two solutions exist for wave frequency, which are affected by the radius of waveguide and the roots of the Bessel function. The damping and growing modes are found to be enhanced by an increase of the radius. However, an increase of electron collision frequency would suppress the damping and the growing modes of the propagating space-charge wave in a cylindrical waveguide plasma.
NASA Astrophysics Data System (ADS)
Zhang, Meimei; Li, Zhen; Tian, Bangsen; Zhou, Jianmin; Tang, Panpan
2016-03-01
A full understanding of the backscattering characteristics of wetlands is necessary for the analysis of the hydrological conditions. In this study, a temporal set of synthetic aperture radar (SAR) imagery, acquired at different frequencies, polarizations and incidence angles over the coastal wetlands of the Liaohe River Delta, China, were used to characterize seasonal variations in radar backscattering coefficient for reed marshes and rice fields. The combination of SAR backscattering intensity and an optical-based normalized difference vegetation index (NDVI) for long time series can provide additional insight into vegetation structural and its hydrological states. After identifying the factors that induce the backscattering and scattering mechanism changes, detailed analysis of L-band ALOS PALSAR interferometric SAR (InSAR) imagery was conducted to study water-level changes under different environmental conditions. In addition, ENVISAT altimetry was used to validate the accuracy of the water-level changes estimated using the InSAR technique-this is an effective tool instead of sparsely distributed gauge stations for the validation. Our study demonstrates that L-band SAR data with horizontal polarization is particularly suitable for the extraction of water-level changes in the study area; however, vertically-polarized C-band data may also be useful where the density of herbaceous vegetation is low at the initial stage. It is also shown that integrated analysis of the backscattering mechanism and interferometric characteristics using multi-mode SAR can considerably enhance the reliability of the water-level retrieval scheme and better capture the spatial distribution of hydrological patterns.
NASA Astrophysics Data System (ADS)
Yoshizawa, K.; Kennett, B. L. N.
2015-12-01
Seismic surface waves are the major source of information to delineate the lateral heterogeneity and anisotropy in the upper mantle. S-wave radial anisotropy representing the difference between SV and SH velocities is often discussed with the seismic properties of the lithosphere-asthenosphere transition (LAT) and the mid-lithosphere discontinuity (MLD). Such boundaries have been studied well by body-wave receiver functions, which have a good sensitivity to the sharpness of boundaries. Surface waves are rather insensitive to the boundary sharpness, but can delineate the spatial distributions of shear wave speeds and radial anisotropy in the upper mantle, which can be alternative constraints on LAT and MLD. We have recently constructed a radially anisotropic 3-D S wave speed model of the Australian continent from multi-mode Love and Rayleigh waves with enhanced ray coverage. In the inversions for S-wave radial anisotropy, we can use either parameterizations for SH and SV velocities, or for dimensionless radially anisotropic parameter ξ=(Vsh/Vsv)2. Both are theoretically the same, but this difference causes non-negligible effects on the estimated radial anisotropy, mainly due to the different sensitivities of Love-wave phase speeds to the structural parameters. Synthetic experiments and data variance reductions suggest the former is the better choice. The LAT throughout the continent can be estimated by the vertical velocity gradient of the isotropic S-wave model. The radial anisotropy with the suitable model parameterization shows strong anisotropy with faster SH velocity in the asthenosphere, suggesting the influence of strong shear beneath the fast drifting Australian continent. We can also identify the clear vertical changes in the radial anisotropy profiles at the MLD depth estimated from earlier receiver function studies in cratonic regions, which can be a key to elucidate the enigmatic MLD in the continental lithosphere.
NASA Astrophysics Data System (ADS)
Maggi, A.; Tromp, J.; Debayle, E.; Barruol, G.
2005-12-01
We present an anisotropic Sv-wave speed tomographic model for the Pacific Ocean region derived from multi-mode waveform inversion of more than 56,000 vertical component seismograms. Most of the data are from the Global Seismic Network, but we include important data from ten broadband seismographs deployed in French Polynesia as part of the Polynesian Lithosphere and Upper Mantle Experiment. This extra data has improved lateral resolution in the south Pacific region, leading to the identification of localized, vertically trending low velocity anomalies associated with the Society and Macdonald hot-spots. An age-dependent average cross-section of our tomographic model shows the lithosphere thickening and cooling with increasing age as predicted by a purely diffusive cooling mechanism. The tomography was performed assuming 2D frequency-independent Gaussian-shaped sensitivity kernels around the surface wave ray-paths, and ray-theoretical depth dependence of the surface wave sensitivity. We validate the 3D tomographic model by calculating full 3D synthetic seismograms using the spectral element method. We estimate the quality of our tomographic inversion by making multi-taper phase and amplitude measurements of the differences between observed seismograms and 3D synthetics. Preliminary inversion of such measurements made on fundamental mode surface waves indicates that the residual discrepancies between our 3D tomographic model and the real Earth structure are localized in regions of strong upper mantle heterogeneity (e.g. subduction zones), for which the ray-theoretical approximations made during the tomographic inversion are most likely to break down.
NASA Astrophysics Data System (ADS)
Sin, Yongkun; Presser, Nathan; Foran, Brendan; Ives, Neil; Moss, Steven C.
2009-02-01
Extensive investigations by a number of groups have identified catastrophic sudden degradation as the main failure mode in both single-mode and multi-mode InGaAs-AlGaAs strained quantum well (QW) lasers. Significant progress made in performance characteristics of broad-area InGaAs strained QW single emitters in recent years has led to an optical output power of over 20W and a power conversion efficiency of over 70% under CW operation. However, unlike 980nm single-mode lasers that have shown high reliability operation under a high optical power density of ~50MW/cm2, broad-area lasers have not achieved the same level of reliability even under a much lower optical power density of ~5MW/cm2. This paper investigates possible mechanisms that prevent broad-area lasers from achieving high reliability operation by performing accelerated lifetests of these devices and in-depth failure mode analyses of degraded devices with various destructive and non-destructive techniques including EBIC, FIB, and HR-TEM techniques. The diode lasers that we have investigated are commercial MOCVD-grown broad-area strained InGaAs single QW lasers at ~975nm. Both passivated and unpassivated broad-area lasers were studied that yielded catastrophic failures at the front facet and also in the bulk. To investigate the role that generation and propagation of defects plays in degradation processes via recombination enhanced defect reaction (REDR), EBIC was employed to study dark line defects in degraded lasers, failed under different stress conditions, and the correlation between DLDs and stress levels is reported. FIB was then employed to prepare TEM samples from the DLD areas for cross-sectional HR-TEM analysis.
Feshbach resonances and weakly bound molecular states of boson-boson and boson-fermion NaK pairs
NASA Astrophysics Data System (ADS)
Viel, Alexandra; Simoni, Andrea
2016-04-01
We conduct a theoretical study of magnetically induced Feshbach resonances and near-threshold bound states in isotopic NaK pairs. Our calculations accurately reproduce Feshbach spectroscopy data on Na 40K and explain the origin of the observed multiplets in the p wave [Phys. Rev. A 85, 051602(R) (2012), 10.1103/PhysRevA.85.051602]. We apply the model to predict scattering and bound state threshold properties of the boson-boson Na 39K and Na 41K systems. We find that the Na 39K isotopic pair presents broad magnetic Feshbach resonances and favorable ground-state features for producing nonreactive polar molecules by two-photon association. Broad s -wave resonances are also predicted for Na 41K collisions.
NASA Astrophysics Data System (ADS)
Guo, Chu; Poletti, Dario
2016-09-01
Quantum systems in contact with an environment display a rich physics emerging from the interplay between dissipative and Hamiltonian terms. Here we focus on the role of the geometry of the coupling between the system and the baths. Specifically we consider a dissipative boundary driven ladder in the presence of a gauge field that can be implemented with ion microtrap arrays. We show that, depending on the geometry, the currents imposed by the baths can be strongly affected by the gauge field, resulting in nonequilibrium phase transitions. In different phases both the magnitude of the current and its spatial distribution are significantly different. These findings allow for strategies to manipulate and control transport properties in quantum systems.
Leng, Xiaoling; Huang, Guofu; Yao, Lanhui; Ma, Fucheng
2015-01-01
Objective: This study is to investigate the diagnostic role of multi-mode ultrasound in level 4 BI-RADS breast lesions and to establish a Logistic regression model. Methods: Totally 179 patients with 182 sites of breast lesions were enrolled in this study. Preoperatively, the examinations of routine ultrasonography, elastography, contrast-enhanced ultrasonography and three-dimensional color Doppler were performed. Postoperatively, the breast lesions were diagnosed as benign and malignant lesions according to pathological results. Diagnostic indicators of each ultrasound analysis were determined and compared. The relationship between these diagnostic indicators and the benign and malignant features of breast lesions was analyzed by single factor analysis. Logistic regression model was established. Results: The diagnostic indicators with high sensitivity and specificity were tumor edge, enhanced range and score of elastography. Four factors of tumor edge, enhanced order, contrast mode and score of elastography were related with the benign and malignant features of breast lesions. The prediction model was Logit (P) = 0.636 + 4.471X1 + 4.337X2 + 3.753X3 + 3.014X4 + 2.525X5 + 2.105X6. Likelihood ratio test showed that the model was statistically significant (χ2 = 161.876, P < 0.0001). This model could effectively distinguish between benign and malignant tumors (R2 = 0.813, prediction accuracy 92.3%). The differences in sensitivity and specificity between multi-mode ultrasound diagnosis and routine ultrasound diagnosis were statistically significant (P < 0.001). However, there was no significant difference between Logistic regression model and multi-mode ultrasound diagnosis. Conclusion: Multi-mode ultrasound and Logistic regression model are more effective in diagnosing level 4 BI-RADS breast lesions. PMID:26629092
Khachatryan, Vardan
2014-08-29
Our search is reported for massive resonances decaying into a quark and a vector boson (W or Z), or two vector bosons (WW, WZ, or ZZ). The analysis is performed on an inclusive sample of multijet events corresponding to an integrated luminosity of 19.7 fb-1, collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. We found that the search uses novel jet-substructure identification techniques that provide sensitivity to the presence of highly boosted vector bosons decaying into a pair of quarks. Exclusion limits are set at a confidence level of 95%more » on the production of: (i) excited quark resonances q*decaying to qW and qZ for masses less than 3.2 TeV and 2.9 TeV, respectively, (ii) a Randall-Sundrum graviton GRS decaying into WW for masses below 1.2 TeV, and (iii) a heavy partner of the W boson W' decaying into WZ for masses less than 1.7 TeV. For the first time mass limits are set on W' → WZ and GRS → WW in the all-jets final state. The mass limits on q* → qW, q* → qZ, W' → WZ, GRS → WW are the most stringent to date. A model with a “bulk” graviton Gbulk that decays into WW or ZZ bosons is also studied.« less
NASA Astrophysics Data System (ADS)
Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Gonzalez, J. Suarez; Alderweireldt, S.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Luyckx, S.; Ochesanu, S.; Roland, B.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Daci, N.; Heracleous, N.; Kalogeropoulos, A.; Keaveney, J.; Kim, T. J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Léonard, A.; Mohammadi, A.; Perniè, L.; Reis, T.; Seva, T.; Thomas, L.; Velde, C. Vander; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Dildick, S.; Fagot, A.; Garcia, G.; Klein, B.; Mccartin, J.; Rios, A. A. Ocampo; Ryckbosch, D.; Diblen, S. Salva; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jez, P.; Komm, M.; Lemaitre, V.; Liao, J.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Marono, M. Vidal; Garcia, J. M. Vizan; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Martins, M. Correa; Martins, T. Dos Reis; Pol, M. E.; Aldá, W. L.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; De Souza, S. Fonseca; Malbouisson, H.; Malek, M.; Figueiredo, D. Matos; Mundim, L.; Nogima, H.; Da Silva, W. L. Prado; Santaolalla, J.; Santoro, A.; Sznajder, A.; Manganote, E. J. Tonelli; Pereira, A. Vilela; Bernardes, C. A.; Dias, F. A.; Tomei, T. R. Fernandez Perez; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Marinov, A.; Piperov, S.; Rodozov, M.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Du, R.; Jiang, C. H.; Liang, D.; Liang, S.; Plestina, R.; Tao, J.; Wang, X.; Wang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, Y.; Li, Q.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Zhang, L.; Zou, W.; Avila, C.; Sierra, L. F. Chaparro; Florez, C.; Gomez, J. P.; Moreno, B. Gomez; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Mekterovic, D.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; Elgammal, S.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; de Monchenault, G. Hamel; Jarry, P.; Locci, E.; Malcles, J.; Nayak, A.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Busson, P.; Charlot, C.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Filipovic, N.; Florent, A.; de Cassagnac, R. Granier; Mastrolorenzo, L.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Veelken, C.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Chabert, E. C.; Collard, C.; Conte, E.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Boudoul, G.; Brochet, S.; Montoya, C. A. Carrillo; De Oliveira, A. Carvalho Antunes; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Alvarez, J. D. Ruiz; Sabes, D.; Sgandurra, L.; Sordini, V.; Donckt, M. Vander; Verdier, P.; Viret, S.; Xiao, H.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Bontenackels, M.; Calpas, B.; Edelhoff, M.; Feld, L.; Hindrichs, O.; Klein, K.; Ostapchuk, A.; Perieanu, A.; Raupach, F.; Sammet, J.; Schael, S.; Sprenger, D.; Weber, H.; Wittmer, B.; Zhukov, V.; Ata, M.; Caudron, J.; Dietz-Laursonn, E.; Duchardt, D.; Erdmann, M.; Fischer, R.; Güth, A.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Klingebiel, D.; Knutzen, S.; Kreuzer, P.; Merschmeyer, M.; Meyer, A.; Olschewski, M.; Padeken, K.; Papacz, P.; Reithler, H.; Schmitz, S. A.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Weber, M.; Cherepanov, V.; Erdogan, Y.; Flügge, G.; Geenen, H.; Geisler, M.; Ahmad, W. Haj; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Lingemann, J.; Nowack, A.; Nugent, I. M.; Perchalla, L.; Pooth, O.; Stahl, A.; Asin, I.; Bartosik, N.; Behr, J.; Behrenhoff, W.; Behrens, U.; Bell, A. J.; Bergholz, M.; Bethani, A.; Borras, K.; Burgmeier, A.; Cakir, A.; Calligaris, L.; Campbell, A.; Choudhury, S.; Costanza, F.; Pardos, C. Diez; Dooling, S.; Dorland, T.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Flucke, G.; Garcia, J. Garay; Geiser, A.; Gunnellini, P.; Hauk, J.; Hellwig, G.; Hempel, M.; Horton, D.; Jung, H.; Kasemann, M.; Katsas, P.; Kieseler, J.; Kleinwort, C.; Krücker, D.; Lange, W.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Lutz, B.; Mankel, R.; Marfin, I.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mnich, J.; Mussgiller, A.; Naumann-Emme, S.; Novgorodova, O.; Nowak, F.; Ntomari, E.; Perrey, H.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Cipriano, P. M. Ribeiro; Ron, E.; Sahin, M. Ö.; Salfeld-Nebgen, J.; Saxena, P.; Schmidt, R.; Schoerner-Sadenius, T.; Schröder, M.; Spannagel, S.; Trevino, A. D. R. Vargas; Walsh, R.; Wissing, C.; Martin, M. Aldaya; Blobel, V.; Vignali, M. Centis; Erfle, J.; Garutti, E.; Goebel, K.; Görner, M.; Gosselink, M.; Haller, J.; Höing, R. S.; Kirschenmann, H.; Klanner, R.; Kogler, R.; Lange, J.; Lapsien, T.; Lenz, T.; Marchesini, I.; Ott, J.; Peiffer, T.; Pietsch, N.; Rathjens, D.; Sander, C.; Schettler, H.; Schleper, P.; Schlieckau, E.; Schmidt, A.; Seidel, M.; Sibille, J.; Sola, V.; Stadie, H.; Steinbrück, G.; Troendle, D.; Usai, E.; Vanelderen, L.; Barth, C.; Baus, C.; Berger, J.; Böser, C.; Butz, E.; Chwalek, T.; De Boer, W.; Descroix, A.; Dierlamm, A.; Feindt, M.; Hartmann, F.; Hauth, T.; Husemann, U.; Katkov, I.; Kornmayer, A.; Kuznetsova, E.; Pardo, P. Lobelle; Mozer, M. U.; Müller, Th.; Nürnberg, A.; Quast, G.; Rabbertz, K.; Ratnikov, F.; Röcker, S.; Simonis, H. J.; Stober, F. M.; Ulrich, R.; Wagner-Kuhr, J.; Wayand, S.; Weiler, T.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Markou, A.; Markou, C.; Psallidas, A.; Topsis-Giotis, I.; Gouskos, L.; Panagiotou, A.; Saoulidou, N.; Stiliaris, E.; Aslanoglou, X.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Bencze, G.; Hajdu, C.; Hidas, P.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Molnar, J.; Palinkas, J.; Szillasi, Z.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Swain, S. K.; Beri, S. B.; Bhatnagar, V.; Dhingra, N.; Gupta, R.; Kalsi, A. K.; Kaur, M.; Mittal, M.; Nishu, N.; Singh, J. B.; Kumar, Ashok; Kumar, Arun; Ahuja, S.; Bhardwaj, A.; Choudhary, B. C.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, V.; Banerjee, S.; Bhattacharya, S.; Chatterjee, K.; Dutta, S.; Gomber, B.; Jain, Sa.; Jain, Sh.; Khurana, R.; Modak, A.; Mukherjee, S.; Roy, D.; Sarkar, S.; Sharan, M.; Abdulsalam, A.; Dutta, D.; Kailas, S.; Kumar, V.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Chatterjee, R. M.; Ganguly, S.; Ghosh, S.; Guchait, M.; Gurtu, A.; Kole, G.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Mohanty, G. B.; Parida, B.; Sudhakar, K.; Wickramage, N.; Banerjee, S.; Dewanjee, R. K.; Dugad, S.; Bakhshiansohi, H.; Behnamian, H.; Etesami, S. M.; Fahim, A.; Goldouzian, R.; Jafari, A.; Khakzad, M.; Najafabadi, M. Mohammadi; Naseri, M.; Mehdiabadi, S. Paktinat; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Barbone, L.; Calabria, C.; Chhibra, S. S.; Colaleo, A.; Creanza, D.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Maggi, M.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Selvaggi, G.; Silvestris, L.; Singh, G.; Venditti, R.; Verwilligen, P.; Zito, G.; Abbiendi, G.; Benvenuti, A. C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. 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J.; Lee, S.; Oh, Y. D.; Park, H.; Sakharov, A.; Son, D. C.; Kim, J. Y.; Song, S.; Choi, S.; Gyun, D.; Hong, B.; Jo, M.; Kim, H.; Kim, Y.; Lee, B.; Lee, K. S.; Park, S. K.; Roh, Y.; Choi, M.; Kim, J. H.; Park, I. C.; Park, S.; Ryu, G.; Ryu, M. S.; Choi, Y.; Choi, Y. K.; Goh, J.; Kwon, E.; Lee, J.; Seo, H.; Yu, I.; Juodagalvis, A.; Komaragiri, J. R.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; La Cruz, I. Heredia-de; Lopez-Fernandez, R.; SanchezHernandez, A.; Moreno, S. Carrillo; Valencia, F. Vazquez; Pedraza, I.; Ibarguen, H. A. Salazar; Linares, E. Casimiro; Pineda, A. Morelos; Krofcheck, D.; Butler, P. H.; Reucroft, S.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khalid, S.; Khan, W. A.; Khurshid, T.; Shah, M. 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I.; Vlimant, J. R.; Wardle, N.; Wöhri, H. K.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; König, S.; Kotlinski, D.; Langenegger, U.; Renker, D.; Rohe, T.; Bachmair, F.; Bäni, L.; Bianchini, L.; Bortignon, P.; Buchmann, M. A.; Casal, B.; Chanon, N.; Deisher, A.; Dissertori, G.; Dittmar, M.; Donegà, M.; Dünser, M.; Eller, P.; Grab, C.; Hits, D.; Lustermann, W.; Mangano, B.; Marini, A. C.; del Arbol, P. Martinez Ruiz; Meister, D.; Mohr, N.; Nägeli, C.; Nef, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pauss, F.; Peruzzi, M.; Quittnat, M.; Rebane, L.; Ronga, F. J.; Rossini, M.; Starodumov, A.; Takahashi, M.; Theofilatos, K.; Wallny, R.; Weber, H. A.; Amsler, C.; Canelli, M. F.; Chiochia, V.; De Cosa, A.; Hinzmann, A.; Hreus, T.; Rikova, M. Ivova; Kilminster, B.; Mejias, B. Millan; Ngadiuba, J.; Robmann, P.; Snoek, H.; Taroni, S.; Verzetti, M.; Yang, Y.; Cardaci, M.; Chen, K. H.; Ferro, C.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Volpe, R.; Yu, S. 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D.; Symonds, P.; Teodorescu, L.; Turner, M.; Dittmann, J.; Hatakeyama, K.; Kasmi, A.; Liu, H.; Scarborough, T.; Charaf, O.; Cooper, S. I.; Henderson, C.; Rumerio, P.; Avetisyan, A.; Bose, T.; Fantasia, C.; Heister, A.; Lawson, P.; Richardson, C.; Rohlf, J.; Sperka, D.; John, J. St.; Sulak, L.; Alimena, J.; Bhattacharya, S.; Christopher, G.; Cutts, D.; Demiragli, Z.; Ferapontov, A.; Garabedian, A.; Heintz, U.; Jabeen, S.; Kukartsev, G.; Laird, E.; Landsberg, G.; Luk, M.; Narain, M.; Segala, M.; Sinthuprasith, T.; Speer, T.; Swanson, J.; Breedon, R.; Breto, G.; De La Barca Sanchez, M. Calderon; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Gardner, M.; Ko, W.; Lander, R.; Miceli, T.; Mulhearn, M.; Pellett, D.; Pilot, J.; Ricci-Tam, F.; Searle, M.; Shalhout, S.; Smith, J.; Squires, M.; Stolp, D.; Tripathi, M.; Wilbur, S.; Yohay, R.; Cousins, R.; Everaerts, P.; Farrell, C.; Hauser, J.; Ignatenko, M.; Rakness, G.; Takasugi, E.; Valuev, V.; Weber, M.; Babb, J.; Clare, R.; Ellison, J.; Gary, J. W.; Hanson, G.; Heilman, J.; Jandir, P.; Kennedy, E.; Lacroix, F.; Liu, H.; Long, O. R.; Luthra, A.; Malberti, M.; Nguyen, H.; Shrinivas, A.; Sturdy, J.; Sumowidagdo, S.; Wimpenny, S.; Andrews, W.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; D'Agnolo, R. T.; Evans, D.; Holzner, A.; Kelley, R.; Lebourgeois, M.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Palmer, C.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Sudano, E.; Tadel, M.; Tu, Y.; Vartak, A.; Würthwein, F.; Yagil, A.; Yoo, J.; Barge, D.; Bradmiller-Feld, J.; Campagnari, C.; Danielson, T.; Dishaw, A.; Flowers, K.; Sevilla, M. 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F.; Matchev, K.; Milenovic, P.; Mitselmakher, G.; Muniz, L.; Rinkevicius, A.; Shchutska, L.; Skhirtladze, N.; Snowball, M.; Yelton, J.; Zakaria, M.; Gaultney, V.; Hewamanage, S.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Adams, T.; Askew, A.; Bochenek, J.; Diamond, B.; Haas, J.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Baarmand, M. M.; Hohlmann, M.; Kalakhety, H.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Bazterra, V. E.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Khalatyan, S.; Kurt, P.; Moon, D. H.; O'Brien, C.; Silkworth, C.; Turner, P.; Varelas, N.; Albayrak, E. A.; Bilki, B.; Clarida, W.; Dilsiz, K.; Duru, F.; Haytmyradov, M.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Rahmat, R.; Sen, S.; Tan, P.; Tiras, E.; Wetzel, J.; Yetkin, T.; Yi, K.; Barnett, B. A.; Blumenfeld, B.; Bolognesi, S.; Fehling, D.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Swartz, M.; Xin, Y.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Gray, J.; Kenny, R. P.; Murray, M.; Noonan, D.; Sanders, S.; Sekaric, J.; Stringer, R.; Wang, Q.; Wood, J. S.; Barfuss, A. F.; Chakaberia, I.; Ivanov, A.; Khalil, S.; Makouski, M.; Maravin, Y.; Saini, L. K.; Shrestha, S.; Svintradze, I.; Gronberg, J.; Lange, D.; Rebassoo, F.; Wright, D.; Baden, A.; Calvert, B.; Eno, S. C.; Gomez, J. A.; Hadley, N. J.; Kellogg, R. G.; Kolberg, T.; Lu, Y.; Marionneau, M.; Mignerey, A. C.; Pedro, K.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Bauer, G.; Busza, W.; Cali, I. A.; Chan, M.; Di Matteo, L.; Dutta, V.; Ceballos, G. Gomez; Goncharov, M.; Gulhan, D.; Klute, M.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Ma, T.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Stephans, G. S. F.; Stöckli, F.; Sumorok, K.; Velicanu, D.; Veverka, J.; Wyslouch, B.; Yang, M.; Zanetti, M.; Zhukova, V.; Dahmes, B.; De Benedetti, A.; Gude, A.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Mans, J.; Pastika, N.; Rusack, R.; Singovsky, A.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Suarez, R. Gonzalez; Keller, J.; Knowlton, D.; Kravchenko, I.; Lazo-Flores, J.; Malik, S.; Meier, F.; Snow, G. R.; Dolen, J.; Godshalk, A.; Iashvili, I.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Haley, J.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Trocino, D.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Velasco, M.; Won, S.; Brinkerhoff, A.; Chan, K. M.; Drozdetskiy, A.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Luo, W.; Lynch, S.; Marinelli, N.; Pearson, T.; Planer, M.; Ruchti, R.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hill, C.; Hughes, R.; Kotov, K.; Ling, T. Y.; Puigh, D.; Rodenburg, M.; Smith, G.; Vuosalo, C.; Winer, B. L.; Wolfe, H.; Wulsin, H. W.; Berry, E.; Driga, O.; Elmer, P.; Hebda, P.; Hunt, A.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Piroué, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zenz, S. C.; Zuranski, A.; Brownson, E.; Mendez, H.; Vargas, J. E. Ramirez; Alagoz, E.; Barnes, V. E.; Benedetti, D.; Bolla, G.; Bortoletto, D.; De Mattia, M.; Everett, A.; Hu, Z.; Jha, M. K.; Jones, M.; Jung, K.; Kress, M.; Leonardo, N.; Pegna, D. Lopes; Maroussov, V.; Merkel, P.; Miller, D. H.; Neumeister, N.; Radburn-Smith, B. C.; Shipsey, I.; Silvers, D.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Yoo, H. D.; Zablocki, J.; Zheng, Y.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Ecklund, K. M.; Geurts, F. J. M.; Li, W.; Michlin, B.; Padley, B. P.; Redjimi, R.; Roberts, J.; Zabel, J.; Betchart, B.; Bodek, A.; Covarelli, R.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Garcia-Bellido, A.; Goldenzweig, P.; Han, J.; Harel, A.; Khukhunaishvili, A.; Miner, D. C.; Petrillo, G.; Vishnevskiy, D.; Ciesielski, R.; Demortier, L.; Goulianos, K.; Mesropian, C.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Lath, A.; Panwalkar, S.; Park, M.; Patel, R.; Rekovic, V.; Salur, S.; Schnetzer, S.; Seitz, C.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Kamon, T.; Khotilovich, V.; Krutelyov, V.; Montalvo, R.; Osipenkov, I.; Pakhotin, Y.; Perloff, A.; Roe, J.; Rose, A.; Safonov, A.; Sakuma, T.; Suarez, I.; Tatarinov, A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kovitanggoon, K.; Kunori, S.; Lee, S. W.; Libeiro, T.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Sharma, M.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Arenton, M. W.; Boutle, S.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Wood, J.; Gollapinni, S.; Harr, R.; Karchin, P. E.; Don, C. Kottachchi Kankanamge; Lamichhane, P.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Dasu, S.; Duric, S.; Friis, E.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Klukas, J.; Lanaro, A.; Lazaridis, C.; Levine, A.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ross, I.; Sarangi, T.; Savin, A.; Smith, W. H.; Woods, N.
2014-08-01
A search is reported for massive resonances decaying into a quark and a vector boson (W or Z), or two vector bosons (WW, WZ, or ZZ). The analysis is performed on an inclusive sample of multijet events corresponding to an integrated luminosity of 19.7 fb-1, collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. The search uses novel jet-substructure identification techniques that provide sensitivity to the presence of highly boosted vector bosons decaying into a pair of quarks. Exclusion limits are set at a confidence level of 95% on the production of: (i) excited quark resonances q*decaying to qW and qZ for masses less than 3.2 TeV and 2.9 TeV, respectively, (ii) a Randall-Sundrum graviton GRS decaying into WW for masses below 1.2 TeV, and (iii) a heavy partner of the W boson W' decaying into WZ for masses less than 1.7 TeV. For the first time mass limits are set on W' → WZ and GRS → WW in the all-jets final state. The mass limits on q* → qW, q* → qZ, W' → WZ, GRS → WW are the most stringent to date. A model with a "bulk" graviton Gbulk that decays into WW or ZZ bosons is also studied. [Figure not available: see fulltext.
Khachatryan, Vardan
2014-08-29
Our search is reported for massive resonances decaying into a quark and a vector boson (W or Z), or two vector bosons (WW, WZ, or ZZ). The analysis is performed on an inclusive sample of multijet events corresponding to an integrated luminosity of 19.7 fb^{-1}, collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. We found that the search uses novel jet-substructure identification techniques that provide sensitivity to the presence of highly boosted vector bosons decaying into a pair of quarks. Exclusion limits are set at a confidence level of 95% on the production of: (i) excited quark resonances q*decaying to qW and qZ for masses less than 3.2 TeV and 2.9 TeV, respectively, (ii) a Randall-Sundrum graviton GRS decaying into WW for masses below 1.2 TeV, and (iii) a heavy partner of the W boson W' decaying into WZ for masses less than 1.7 TeV. For the first time mass limits are set on W' → WZ and G_{RS} → WW in the all-jets final state. The mass limits on q* → qW, q* → qZ, W' → WZ, G_{RS} → WW are the most stringent to date. A model with a “bulk” graviton G_{bulk} that decays into WW or ZZ bosons is also studied.
NASA Astrophysics Data System (ADS)
Kruse, Kevin; Middlebrook, Christopher
2015-01-01
A laser direct writing (LDW) method is implemented as a cost efficient polymer waveguide (WG) fabrication method for prototyping large substrates for optical backplanes and optical interconnection assemblies. The LDW setup utilizes a 3-axis air-bearing motion platform to reduce WG fabrication error to within ±0.15 μm. A UV laser diode coupled single mode fiber with a focusing lens module is capable of LDW WGs at both multimode (50 μm) and single mode (6 μm) dimensions. Correlation between LDW parameters and fabricated WG dimensions using Dow Corning® OE-4140 UV-Cured Optical Elastomer (ncore = 1.5142, nclad = 1.5064) is discussed theoretically and confirmed experimentally for both applications. A theoretical model is developed and utilized for producing LDW multi-mode (0.04 dB/cm, λ = 850 nm) and single mode (0.55 dB/cm, λ = 1310 nm) WGs. Measured propagation losses of LDW WGs are comparable to losses of photolithographic multi-mode (0.04 dB/cm @ 850 nm) and single mode (0.59 dB/cm @ 1310 nm) WG builds. LDW multi-mode and single mode WG radial bend and crossing losses are evaluated for advanced optical communication channel routing capabilities and do not exhibit significant deviations from photolithographic-manufactured WG device loss.
Permanents, bosons and linear optics
NASA Astrophysics Data System (ADS)
Vlasov, Alexander Yu
2017-10-01
The particular complexity of linear quantum optical networks has received certain deserved attention recently due to the possible implications for the theory of quantum computation. Two relevant boson models are discussed in the presented work. The symmetric product of the Hilbert spaces produces a rather abstract model; the second one is obtained by quantization of the harmonic oscillator. In contrast to the considered bosonic processes, the so-called ‘fermionic linear optics’ is effectively simulated on a classical computer. The comparison of the bosonic and fermionic case clarifies the controversy, and the more elaborate oscillator model provides a deeper analogy.
Kondo length in bosonic lattices
NASA Astrophysics Data System (ADS)
Giuliano, Domenico; Sodano, Pasquale; Trombettoni, Andrea
2017-09-01
Motivated by the fact that the low-energy properties of the Kondo model can be effectively simulated in spin chains, we study the realization of the effect with bond impurities in ultracold bosonic lattices at half filling. After presenting a discussion of the effective theory and of the mapping of the bosonic chain onto a lattice spin Hamiltonian, we provide estimates for the Kondo length as a function of the parameters of the bosonic model. We point out that the Kondo length can be extracted from the integrated real-space correlation functions, which are experimentally accessible quantities in experiments with cold atoms.
Correlations of excited states for sd bosons in the presence of random interactions
Lei, Y.; Zhao, Y. M.; Yoshida, N.; Arima, A.
2011-04-15
In this work we study the yrast states of sd-boson systems in the presence of random interactions. It is found that the yrast states with spin-zero ground states among the random ensemble exhibit strong correlations, characterized by anharmonic vibration, s-boson or d-boson condensation, as well as vibrational and rotational motions. We study these correlations explicitly based on their wave functions and the features of two-body interactions in the random ensemble.
Nelson, Ann E.
2008-05-01
We show that for a force mediated by a vector particle coupled to a conserved U(1) charge, the apparent range and strength can depend on the size and density of the source, and the proximity to other sources. This chameleon effect is due to screening from a light charged scalar. Such screening can weaken astrophysical constraints on new gauge bosons. As an example we consider the constraints on chameleonic gauged B-L. We show that although Casimir measurements greatly constrain any B-L force much stronger than gravity with range longer than 0.1 {mu}m, there remains an experimental window for a long-range chameleonic B-L force. Such a force could be much stronger than gravity, and long or infinite range in vacuum, but have an effective range near the surface of the earth which is less than a micron.
Draper, P.; Liu, T.; Wagner, C. E. M.; Wang, L.-T.; Zhang, H.
2011-03-24
We study a limit of the nearly Peccei-Quinn-symmetric next-to-minimal supersymmetric standard model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally coexist three light singletlike particles: a scalar, a pseudoscalar, and a singlinolike DM candidate, all with masses of order 0.1-10 GeV. The decay of a standard model-like Higgs boson to pairs of the light scalars or pseudoscalars is generically suppressed, avoiding constraints from collider searches for these channels. For a certain parameter window annihilation into the light pseudoscalar and exchange of the light scalar with nucleons allow the singlino to achieve the correct relic density and a large direct-detection cross section consistent with the DM direct-detection experiments, CoGeNT and DAMA/LIBRA, preferred region simultaneously. This parameter space is consistent with experimental constraints from LEP, the Tevatron, ?, and flavor physics.
NASA Astrophysics Data System (ADS)
White, Andrew; Broome, Matthew; Fedrizzi, Alessandro; Rahimi-Keshari, Saleh; Ralph, Timothy; Dove, Justin; Aaronson, Scott
2013-03-01
Quantum computers are unnecessary for exponentially-efficient computation or simulation if the Extended Church-Turing thesis--a foundational tenet of computer science--is correct. The thesis would be directly contradicted by a physical device that efficiently performs a task believed to be intractable for classical computers. Such a task is BOSONSAMPLING: obtaining a distribution of n bosons scattered by some linear-optical unitary process. Here we test the central premise of BOSONSAMPLING, experimentally verifying that the amplitudes of 3-photon scattering processes are given by the permanents of submatrices generated from a unitary describing a 6-mode integrated optical circuit. We find the protocol to be robust, working even with the unavoidable effects of photon loss, non-ideal sources, and imperfect detection. Strong evidence against the Extended-Church-Turing thesis will come from scaling to large numbers of photons, which is a much simpler task than building a universal quantum computer.
NASA Astrophysics Data System (ADS)
Dawson, Joshua
A novel multi-mode implementation of a pulsed detonation engine, put forth by Wilson et al., consists of four modes; each specifically designed to capitalize on flow features unique to the various flow regimes. This design enables the propulsion system to generate thrust through the entire flow regime. The Multi-Mode Ejector-Augmented Pulsed Detonation Rocket Engine operates in mode one during take-off conditions through the acceleration to supersonic speeds. Once the mixing chamber internal flow exceeds supersonic speed, the propulsion system transitions to mode two. While operating in mode two, supersonic air is compressed in the mixing chamber by an upstream propagating detonation wave and then exhausted through the convergent-divergent nozzle. Once the velocity of the air flow within the mixing chamber exceeds the Chapman-Jouguet Mach number, the upstream propagating detonation wave no longer has sufficient energy to propagate upstream and consequently the propulsive system shifts to mode three. As a result of the inability of the detonation wave to propagate upstream, a steady oblique shock system is established just upstream of the convergent-divergent nozzle to initiate combustion. And finally, the propulsion system progresses on to mode four operation, consisting purely of a pulsed detonation rocket for high Mach number flight and use in the upper atmosphere as is needed for orbital insertion. Modes three and four appear to be a fairly significant challenge to implement, while the challenge of implementing modes one and two may prove to be a more practical goal in the near future. A vast number of potential applications exist for a propulsion system that would utilize modes one and two, namely a high Mach number hypersonic cruise vehicle. There is particular interest in the dynamics of mode one operation, which is the subject of this research paper. Several advantages can be obtained by use of this technology. Geometrically the propulsion system is fairly
'True' bosonic coupling strength in strongly correlated superconductors.
Iwasawa, Hideaki; Yoshida, Yoshiyuki; Hase, Izumi; Shimada, Kenya; Namatame, Hirofumi; Taniguchi, Masaki; Aiura, Yoshihiro
2013-01-01
Clarifying the coupling between electrons and bosonic excitations (phonons or magnetic fluctuations) that mediate the formation of Cooper pairs is pivotal to understand superconductivity. Such coupling effects are contained in the electron self-energy, which is experimentally accessible via angle-resolved photoemission spectroscopy (ARPES). However, in unconventional superconductors, identifying the nature of the electron-boson coupling remains elusive partly because of the significant band renormalization due to electron correlation. Until now, to quantify the electron-boson coupling, the self-energy is most often determined by assuming a phenomenological 'bare' band. Here, we demonstrate that the conventional procedure underestimates the electron-boson coupling depending on the electron-electron coupling, even if the self-energy appears to be self-consistent via the Kramers-Kronig relation. Our refined method explains well the electron-boson and electron-electron coupling strength in ruthenate superconductor Sr2RuO4, calling for a critical revision of the bosonic coupling strength from ARPES self-energy in strongly correlated electron systems.
‘True’ bosonic coupling strength in strongly correlated superconductors
Iwasawa, Hideaki; Yoshida, Yoshiyuki; Hase, Izumi; Shimada, Kenya; Namatame, Hirofumi; Taniguchi, Masaki; Aiura, Yoshihiro
2013-01-01
Clarifying the coupling between electrons and bosonic excitations (phonons or magnetic fluctuations) that mediate the formation of Cooper pairs is pivotal to understand superconductivity. Such coupling effects are contained in the electron self-energy, which is experimentally accessible via angle-resolved photoemission spectroscopy (ARPES). However, in unconventional superconductors, identifying the nature of the electron-boson coupling remains elusive partly because of the significant band renormalization due to electron correlation. Until now, to quantify the electron-boson coupling, the self-energy is most often determined by assuming a phenomenological ‘bare’ band. Here, we demonstrate that the conventional procedure underestimates the electron-boson coupling depending on the electron-electron coupling, even if the self-energy appears to be self-consistent via the Kramers-Kronig relation. Our refined method explains well the electron-boson and electron-electron coupling strength in ruthenate superconductor Sr2RuO4, calling for a critical revision of the bosonic coupling strength from ARPES self-energy in strongly correlated electron systems. PMID:23722675
NASA Astrophysics Data System (ADS)
Sin, Yongkun; Presser, Nathan; Lingley, Zachary; Brodie, Miles; Foran, Brendan; Moss, Steven C.
2016-03-01
High power single-mode (SM) and multi-mode (MM) InGaAs-AlGaAs strained quantum well (QW) lasers are critical components for both telecommunications and potential space satellite communications systems. However, little has been reported on failure modes of state-of-the-art SM InGaAs-AlGaAs strained QW lasers although it is crucial to understand failure modes and underlying degradation mechanisms in developing these lasers that meet lifetime requirements for space satellite systems, where extremely high reliability of these lasers is required. Our present study addresses the aforementioned issues by performing long-term life tests under different test conditions followed by failure mode analysis (FMA) and physics of failure investigation. We performed long-term accelerated life-tests on state-of-the-art SM and MM InGaAs-AlGaAs strained QW lasers under ACC (automatic current control) mode. Our life-tests have accumulated over 25,000 test hours for SM lasers and over 35,000 test hours for MM lasers. FMA was performed on failed SM lasers using electron beam induced current (EBIC). This technique allowed us to identify failure types by observing dark line defects. All the SM failures we studied showed catastrophic and sudden degradation and all of these failures were bulk failures. Our group previously reported that bulk failure or COBD (catastrophic optical bulk damage) is the dominant failure mode of MM InGaAs-AlGaAs strained QW lasers. To the best of our knowledge, this is the first report demonstrating that the dominant failure mode of both SM and MM InGaAs-AlGaAs strained QW lasers is the bulk failure. Since degradation mechanisms responsible for COBD are still not well understood, we also employed other techniques including focused ion beam (FIB) processing and high-resolution TEM to further study dark line defects and dislocations in post-aged SM and MM lasers. Our long-term life test results and FMA results are reported.
Lincoln, Don
2016-07-12
Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.
Lincoln, Don
2011-07-07
Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.
Exciton-exciton scattering: Composite boson versus elementary boson
NASA Astrophysics Data System (ADS)
Combescot, M.; Betbeder-Matibet, O.; Combescot, R.
2007-05-01
This paper shows the necessity of introducing a quantum object, the “coboson,” to properly describe, through a fermion scheme, any composite particle, such as the exciton, which is made of two fermions. Although commonly dealt with as elementary bosons, these composite bosons—cobosons in short—differ from them due to their composite nature which makes the handling of their many-body effects quite different from the existing treatments valid for elementary bosons. As a direct consequence of this composite nature, there is no correct way to describe the interaction between cobosons as a potential V . This is rather dramatic because, with the Hamiltonian not written as H=H0+V , all the usual approaches to many-body effects fail. In particular, the standard form of the Fermi golden rule, written in terms of V , cannot be used to obtain the transition rates of two cobosons. To get them, we have had to construct an unconventional expression for this Fermi golden rule in which H only appears. Making use of this expression, we give here a detailed calculation of the time evolution of two excitons. We compare the results of this exact approach with the ones obtained by using an effective bosonic Hamiltonian in which the excitons are considered as elementary bosons with effective scatterings between them, these scatterings resulting from an elaborate mapping between the two-fermion space and the ideal boson space. We show that the relation between the inverse lifetime and the sum of the transition rates for elementary bosons differs from the one of the composite bosons by a factor of 1/2 , so that it is impossible to find effective scatterings between bosonic excitons giving these two physical quantities correctly, whatever the mapping from composite bosons to elementary bosons is. The present paper thus constitutes a strong mathematical proof that, in spite of a widely spread belief, we cannot forget the composite nature of these cobosons, even in the extremely low
Quantum Two-breathers Formed by Ultracold Bosonic Atoms in Optical Lattices
NASA Astrophysics Data System (ADS)
Tang, Bing
2016-06-01
Two-discrete breathers are the bound states of two localized modes that can appear in classical nonlinear lattices. I investigate the quantum signature of two-discrete breathers in the system of ultracold bosonic atoms in optical lattices, which is modeled as Bose-Hubbard model containing n bosons. When the number of bosons is small, I find numerically quantum two-breathers by making use of numerical diagonalization and perturbation theory. For the cases of a large number of bosons, I can successfully construct quantum two-breather states in the Hartree approximation.
NASA Astrophysics Data System (ADS)
Ireland, Laralee Gordon
A numerical model was developed to investigate the possibility of implementing active control (ANC) to minimize noise radiation from high-bypass turbofan engines. Previous experimental work on the NASA Glenn Research Center active noise control fan (ANCF) was encouraging, but the question remained whether the modal approach investigated could be effective on real engines. The engine model developed for this research project uses an indirect boundary element method, implemented with Sysnoise, and a multi-mode Newton's algorithm, implemented with MATLAB(TM), to simulate the active control. Noise from the inlet was targeted. Both the experimental and numerical results based on the NASA ANCF simplified cylindrical engine geometry indicate overall reductions in the m = 2 component of the noise. Reductions obtained at the numerical sensor rings range from 17 dB to 63 dB and at a plane in the duct inlet, -8 dB to 33 dB. Rings mounted on the inlet duct are unable to accurately predict the total reduction of the inlet field, but the controller is still able to effectively reduce the total acoustic field. Generally, one sensor ring and one actuator ring per propagating mode were necessary to control the inlet field. At frequencies close to the cut-off frequency of a mode, an additional sensor and actuator ring were needed to adequately control the inlet field due to the evanescent mode. A more realistic, but still axisymmetric, engine geometry based on the GE CF6-80C engine was developed and the same algorithm used. Reductions obtained at the sensor rings range from 4 dB to 56 dB and at the duct inlet plane, from 12 dB to 26 dB. The overall far field noise radiation from the engine remained unchanged (0.4 dB) or decreased slightly (3.6 dB). The inlet noise was controlled at all frequencies but the noise from the exhaust was increased. The effect of inlet control on the exhaust radiation suggests the need for a controller that targets both the inlet and exhaust noise
Statistical benchmark for BosonSampling
NASA Astrophysics Data System (ADS)
Walschaers, Mattia; Kuipers, Jack; Urbina, Juan-Diego; Mayer, Klaus; Tichy, Malte Christopher; Richter, Klaus; Buchleitner, Andreas
2016-03-01
Boson samplers—set-ups that generate complex many-particle output states through the transmission of elementary many-particle input states across a multitude of mutually coupled modes—promise the efficient quantum simulation of a classically intractable computational task, and challenge the extended Church-Turing thesis, one of the fundamental dogmas of computer science. However, as in all experimental quantum simulations of truly complex systems, one crucial problem remains: how to certify that a given experimental measurement record unambiguously results from enforcing the claimed dynamics, on bosons, fermions or distinguishable particles? Here we offer a statistical solution to the certification problem, identifying an unambiguous statistical signature of many-body quantum interference upon transmission across a multimode, random scattering device. We show that statistical analysis of only partial information on the output state allows to characterise the imparted dynamics through particle type-specific features of the emerging interference patterns. The relevant statistical quantifiers are classically computable, define a falsifiable benchmark for BosonSampling, and reveal distinctive features of many-particle quantum dynamics, which go much beyond mere bunching or anti-bunching effects.
Finite-temperature phase diagram of the three-dimensional hard-core bosonic t-J model
Nakano, Yuki; Matsui, Tetsuo; Ishima, Takumi; Kobayashi, Naohiro; Ichinose, Ikuo; Sakakibara, Kazuhiko
2011-06-15
We study the three-dimensional bosonic t-J model, that is, the t-J model of 'bosonic electrons' at finite temperatures. This model describes a system of an isotropic antiferromagnet with doped bosonic holes and is closely related to systems of two-component bosons in an optical lattice. The bosonic 'electron' operator B{sub x{sigma}} at the site x with a two-component spin {sigma}(=1,2) is treated as a hard-core boson operator and represented by a composite of two slave particles: a spinon described by a Schwinger boson (CP{sup 1} boson) z{sub x}{sigma} and a holon described by a hard-core-boson field {phi}{sub x} as B{sub x}{sigma}={phi}{sub x}{sup {dagger}}z{sub x}{sigma}. By means of Monte Carlo simulations of this bosonic t-J model, we study its phase structure and the possible phenomena like appearance of antiferromagnetic long-range order, Bose-Einstein condensation, phase separation, etc. Obtained results show that the bosonic t-J model has a phase diagram that suggests some interesting implications for high-temperature superconducting materials.
Rotating boson stars in five dimensions
Hartmann, Betti; Kleihaus, Burkhard; Kunz, Jutta; List, Meike
2010-10-15
We study rotating boson stars in five spacetime dimensions. The boson fields consist of a complex doublet scalar field. Considering boson stars rotating in two orthogonal planes with both angular momenta of equal magnitude, a special ansatz for the boson field and the metric allows for solutions with nontrivial dependence on the radial coordinate only. The charge of the scalar field equals the sum of the angular momenta. The rotating boson stars are globally regular and asymptotically flat. For our choice of a sextic potential, the rotating boson star solutions possess a flat spacetime limit. We study the solutions in flat and curved spacetime.
Mixtures of Bosonic and Fermionic atoms
NASA Astrophysics Data System (ADS)
Albus, Alexander
2003-12-01
The theory of atomic Boson-Fermion mixtures in the dilute limit beyond mean-field is considered in this thesis. Extending the formalism of quantum field theory we derived expressions for the quasi-particle excitation spectra, the ground state energy, and related quantities for a homogenous system to first order in the dilute gas parameter. In the framework of density functional theory we could carry over the previous results to inhomogeneous systems. We then determined to density distributions for various parameter values and identified three different phase regions: (i) a stable mixed regime, (ii) a phase separated regime, and (iii) a collapsed regime. We found a significant contribution of exchange-correlation effects in the latter case. Next, we determined the shift of the Bose-Einstein condensation temperature caused by Boson-Fermion interactions in a harmonic trap due to redistribution of the density profiles. We then considered Boson-Fermion mixtures in optical lattices. We calculated the criterion for stability against phase separation, identified the Mott-insulating and superfluid regimes both, analytically within a mean-field calculation, and numerically by virtue of a Gutzwiller Ansatz. We also found new frustrated ground states in the limit of very strong lattices. ----Anmerkung: Der Autor ist Träger des durch die Physikalische Gesellschaft zu Berlin vergebenen Carl-Ramsauer-Preises 2004 für die jeweils beste Dissertation der vier Universitäten Freie Universität Berlin, Humboldt-Universität zu Berlin, Technische Universität Berlin und Universität Potsdam. Ziel der Arbeit war die systematische theoretische Behandlung von Gemischen aus bosonischen und fermionischen Atomen in einem Parameterbereich, der sich zur Beschreibung von aktuellen Experimenten mit ultra-kalten atomaren Gasen eignet. Zuerst wurde der Formalismus der Quantenfeldtheorie auf homogene, atomare Boson-Fermion Gemische erweitert, um grundlegende Größen wie Quasiteilchenspektren
Analytic boosted boson discrimination
Larkoski, Andrew J.; Moult, Ian; Neill, Duff
2016-05-20
Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D_{2}, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits. By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. In conclusion, our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.
Analytic boosted boson discrimination
Larkoski, Andrew J.; Moult, Ian; Neill, Duff
2016-05-20
Observables which discriminate boosted topologies from massive QCD jets are of great importance for the success of the jet substructure program at the Large Hadron Collider. Such observables, while both widely and successfully used, have been studied almost exclusively with Monte Carlo simulations. In this paper we present the first all-orders factorization theorem for a two-prong discriminant based on a jet shape variable, D2, valid for both signal and background jets. Our factorization theorem simultaneously describes the production of both collinear and soft subjets, and we introduce a novel zero-bin procedure to correctly describe the transition region between these limits.more » By proving an all orders factorization theorem, we enable a systematically improvable description, and allow for precision comparisons between data, Monte Carlo, and first principles QCD calculations for jet substructure observables. Using our factorization theorem, we present numerical results for the discrimination of a boosted Z boson from massive QCD background jets. We compare our results with Monte Carlo predictions which allows for a detailed understanding of the extent to which these generators accurately describe the formation of two-prong QCD jets, and informs their usage in substructure analyses. In conclusion, our calculation also provides considerable insight into the discrimination power and calculability of jet substructure observables in general.« less
NASA Astrophysics Data System (ADS)
Heydarinasab, F.; Abouie, J.
2017-09-01
We introduce an inhomogeneous bosonic mixture composed of two kinds of hard-core and semi-hard-core bosons with different nilpotency conditions and demonstrate that in contrast with the standard hard-core Bose-Hubbard model, our bosonic mixture with nearest- and next-nearest-neighbor interactions on a square lattice develops the checkerboard supersolid phase characterized by the simultaneous superfluid and checkerboard solid orders. Our bosonic mixture is created from a two-orbital Bose-Hubbard model including two kinds of bosons: a single-orbital boson and a two-orbital boson. By mapping the bosonic mixture to an anisotropic inhomogeneous spin model in the presence of a magnetic field, we study the ground-state phase diagram of the model by means of cluster mean field theory and linear spin-wave theory and show that various phases such as solid, superfluid, supersolid, and Mott insulator appear in the phase diagram of the mixture. Competition between the interactions and magnetic field causes the mixture to undergo different kinds of first- and second-order phase transitions. By studying the behavior of the spin-wave excitations, we find the reasons of all first- and second-order phase transitions. We also obtain the temperature phase diagram of the system using cluster mean field theory. We show that the checkerboard supersolid phase persists at finite temperature comparable with the interaction energies of bosons.
Nonlocal Symmetry Reductions for Bosonized Supersymmetric Burgers Equation
NASA Astrophysics Data System (ADS)
Ren, Bo; Lin, Ji; Le, Jia-Yi; Wang, Sheng; Dai, Tian-Zhao
2017-08-01
Based on the bosonization approach, the supersymmetric Burgers (SB) system is transformed to a coupled bosonic system. By solving the bosonized SB (BSB) equation, the difficulties caused by the anticommutative fermionic field of the SB equation can be avoided. The nonlocal symmetry for the BSB equation is obtained by the truncated Painlevé method. By introducing multiple new fields, the finite symmetry transformation for the BSB equation is derived by solving the first Lie’s principle of the prolonged systems. Some group invariant solutions are obtained with the similarity reductions related by the nonlocal symmetry. Supported by the National Natural Science Foundation of China under Grant Nos. 11675146, 11305106, 11472177, 11275129, and the Natural Science Foundation of Zhejiang Province of China under Grant No. LZ15A050001
Chakrabarti, Barnali
2010-01-15
We consider a finite number of trapped bosons in one dimension (1D) interacting through the harmonic Calogero interaction. Using an exact analytic solution for the energy eigenvalues we calculate the condensate fraction, ground-state energy, and specific heat of the system. For weak interaction the behavior of thermodynamic properties is close to that of noninteracting trapped bosons.
Collapse in boson-fermion mixtures with all-repulsive interactions
Prytula, Vladyslav I.; Konotop, Vladimir V.; Perez-Garcia, Victor M.; Vekslerchik, Vadym E.
2007-10-15
We describe the collapse of the bosonic component in a boson-fermion mixture due to the pressure exerted on it by a large fermionic component, leading to collapse in a system with all-repulsive interactions. We describe the phenomena of early collapse and superslow collapse of the mixture.
Chen, Z; Gong, G
2014-06-01
Purpose: To design an external marking body (EMB) that could be visible on computed tomography (CT), magnetic resonance (MR), positron emission tomography (PET) and single-photon emission computed tomography (SPECT) images and to investigate the use of the EMB for multiple medical images registration and fusion in the clinic. Methods: We generated a solution containing paramagnetic metal ions and iodide ions (CT'MR dual-visible solution) that could be viewed on CT and MR images and multi-mode image visible solution (MIVS) that could be obtained by mixing radioactive nuclear material. A globular plastic theca (diameter: 3–6 mm) that mothball the MIVS and the EMB was brought by filling MIVS. The EMBs were fixed on the patient surface and CT, MR, PET and SPECT scans were obtained. The feasibility of clinical application and the display and registration error of EMB among different image modalities were investigated. Results: The dual-visible solution was highly dense on CT images (HU>700). A high signal was also found in all MR scanning (T1, T2, STIR and FLAIR) images, and the signal was higher than subcutaneous fat. EMB with radioactive nuclear material caused a radionuclide concentration area on PET and SPECT images, and the signal of EMB was similar to or higher than tumor signals. The theca with MIVS was clearly visible on all the images without artifact, and the shape was round or oval with a sharp edge. The maximum diameter display error was 0.3 ± 0.2mm on CT and MRI images, and 1.0 ± 0.3mm on PET and SPECT images. In addition, the registration accuracy of the theca center among multi-mode images was less than 1mm. Conclusion: The application of EMB with MIVS improves the registration and fusion accuracy of multi-mode medical images. Furthermore, it has the potential to ameliorate disease diagnosis and treatment outcome.
Duality of boson and fermion: New intermediate-statistics
NASA Astrophysics Data System (ADS)
Chung, Won Sang; Algin, Abdullah
2017-10-01
In this work, we propose a new model for describing an intermediate-statistics particles system. Starting with a deformed grand partition function, we investigate several thermodynamical and statistical properties of a gas model of two-parameter deformed particles. We specifically focus on the low-temperature behavior of the model and the conditions under which either boson condensation or fermion condensation would occur in such a model are discussed. Our results obtained in this study reveal that the present deformed gas model exhibits duality of boson and fermion, and can be useful for approaching the thermostatistics of condensation characteristics in quantum systems.
Proposal for Microwave Boson Sampling
NASA Astrophysics Data System (ADS)
Peropadre, Borja; Guerreschi, Gian Giacomo; Huh, Joonsuk; Aspuru-Guzik, Alán
2016-09-01
Boson sampling, the task of sampling the probability distribution of photons at the output of a photonic network, is believed to be hard for any classical device. Unlike other models of quantum computation that require thousands of qubits to outperform classical computers, boson sampling requires only a handful of single photons. However, a scalable implementation of boson sampling is missing. Here, we show how superconducting circuits provide such platform. Our proposal differs radically from traditional quantum-optical implementations: rather than injecting photons in waveguides, making them pass through optical elements like phase shifters and beam splitters, and finally detecting their output mode, we prepare the required multiphoton input state in a superconducting resonator array, control its dynamics via tunable and dispersive interactions, and measure it with nondemolition techniques.
Interacting Boson Model and nucleons
NASA Astrophysics Data System (ADS)
Otsuka, Takaharu
2012-10-01
An overview on the recent development of the microscopic derivation of the Interacting Boson Model is presented with some remarks not found elsewhere. The OAI mapping is reviewed very briefly, including the basic correspondence from nucleon-pair to boson. The new fermionboson mapping method is introduced, where intrinsic states of nucleons and bosons for a wide variation of shapes play an important role. Nucleon intrinsic states are obtained from mean field models, which is Skyrme model in examples to be shown. This method generates IBM-2 Hamiltonian which can describe and predict various situations of quadrupole collective states, including U(5), SU(3), O(6) and E(5) limits. The method is extended so that rotational response (cranking) can be handled, which enables us to describe rotational bands of strongly deformed nuclei. Thus, we have obtained a unified framework for the microscopic derivation of the IBM covering all known situations of quadrupole collectivity at low energy.
Working Group Report: Higgs Boson
Dawson, Sally; Gritsan, Andrei; Logan, Heather; Qian, Jianming; Tully, Chris; Van Kooten, Rick
2013-10-30
This report summarizes the work of the Energy Frontier Higgs Boson working group of the 2013 Community Summer Study (Snowmass). We identify the key elements of a precision Higgs physics program and document the physics potential of future experimental facilities as elucidated during the Snowmass study. We study Higgs couplings to gauge boson and fermion pairs, double Higgs production for the Higgs self-coupling, its quantum numbers and $CP$-mixing in Higgs couplings, the Higgs mass and total width, and prospects for direct searches for additional Higgs bosons in extensions of the Standard Model. Our report includes projections of measurement capabilities from detailed studies of the Compact Linear Collider (CLIC), a Gamma-Gamma Collider, the International Linear Collider (ILC), the Large Hadron Collider High-Luminosity Upgrade (HL-LHC), Very Large Hadron Colliders up to 100 TeV (VLHC), a Muon Collider, and a Triple-Large Electron Positron Collider (TLEP).
Exotic Gauge Bosons in the 331 Model
Romero, D.; Ravinez, O.; Diaz, H.; Reyes, J.
2009-04-30
We analize the bosonic sector of the 331 model which contains exotic leptons, quarks and bosons (E,J,U,V) in order to satisfy the weak gauge SU(3){sub L} invariance. We develop the Feynman rules of the entire kinetic bosonic sector which will let us to compute some of the Z(0)' decays modes.
Bosonic cascades of indirect excitons
NASA Astrophysics Data System (ADS)
Nalitov, A. V.; De Liberato, S.; Lagoudakis, P.; Savvidis, P. G.; Kavokin, A. V.
2017-08-01
Recently, the concept of the terahertz bosonic cascade laser (BCL) based on a parabolic quantum well (PQW) embedded in a microcavity was proposed. We refine this proposal by suggesting transitions between indirect exciton (IX) states as a source of terahertz emission. We explicitly propose a structure containing a narrow-square QW and a wide-parabolic QW for the realisation of a bosonic cascade. Advantages of this type of structures are in large dipole matrix elements for terahertz transitions and in long exciton radiative lifetimes which are crucial for realisation of threshold and quantum efficiency BCLs.
Andreev Reflection in Bosonic Condensates
Zapata, I.; Sols, F.
2009-05-08
We study the bosonic analog of Andreev reflection at a normal-superfluid interface where the superfluid is a boson condensate. We model the normal region as a zone where nonlinear effects can be neglected. Against the background of a decaying condensate, we identify a novel contribution to the current of reflected atoms. The group velocity of this Andreev reflected component differs from that of the normally reflected one. For a three-dimensional planar or two-dimensional linear interface Andreev reflection is neither specular nor conjugate.
Andreev reflection in bosonic condensates.
Zapata, I; Sols, F
2009-05-08
We study the bosonic analog of Andreev reflection at a normal-superfluid interface where the superfluid is a boson condensate. We model the normal region as a zone where nonlinear effects can be neglected. Against the background of a decaying condensate, we identify a novel contribution to the current of reflected atoms. The group velocity of this Andreev reflected component differs from that of the normally reflected one. For a three-dimensional planar or two-dimensional linear interface Andreev reflection is neither specular nor conjugate.
Auxiliary-Field Monte Carlo Method to Tackle Strong Interactions and Frustration in Lattice Bosons
NASA Astrophysics Data System (ADS)
Malpetti, Daniele; Roscilde, Tommaso
2017-07-01
We introduce a new numerical technique, the bosonic auxiliary-field Monte Carlo method, which allows us to calculate the thermal properties of large lattice-boson systems within a systematically improvable semiclassical approach, and which is virtually applicable to any bosonic model. Our method amounts to a decomposition of the lattice into clusters, and to an ansatz for the density matrix of the system in the form of a cluster-separable state—with nonentangled, yet classically correlated clusters. This approximation eliminates any sign problem, and can be systematically improved upon by using clusters of growing size. Extrapolation in the cluster size allows us to reproduce numerically exact results for the superfluid transition of hard-core bosons on the square lattice, and to provide a solid quantitative prediction for the superfluid and chiral transition of hardcore bosons on the frustrated triangular lattice.
Interaction blockade for bosons in an asymmetric double well
NASA Astrophysics Data System (ADS)
Cosme, Jayson G.; Andersen, Mikkel F.; Brand, Joachim
2017-07-01
The interaction blockade phenomenon isolates the motion of a single quantum particle within a multiparticle system, in particular for coherent oscillations in and out of a region affected by the blockade mechanism. For identical quantum particles with Bose statistics, the presence of the other particles is still felt by a bosonic stimulation factor √{N } that speeds up the coherent oscillations, where N is the number of bosons. Here we propose an experiment to observe this enhancement factor with a small number of bosonic atoms. The proposed protocol realizes an asymmetric double-well potential with multiple optical tweezer laser beams. The ability to adjust bias independently of the coherent coupling between the wells allows the potential to be loaded with different particle numbers while maintaining the resonance condition needed for coherent oscillations. Numerical simulations with up to three bosons in a realistic potential generated by three optical tweezers predict that the relevant avoided level crossing can be probed and the expected bosonic enhancement factor observed.
Kwon, Osung; Park, Kwang-Kyoon; Ra, Young-Sik; Kim, Yong-Su; Kim, Yoon-Ho
2013-10-21
Generation of time-bin entangled photon pairs requires the use of the Franson interferometer which consists of two spatially separated unbalanced Mach-Zehnder interferometers through which the signal and idler photons from spontaneous parametric down-conversion (SPDC) are made to transmit individually. There have been two SPDC pumping regimes where the scheme works: the narrowband regime and the double-pulse regime. In the narrowband regime, the SPDC process is pumped by a narrowband cw laser with the coherence length much longer than the path length difference of the Franson interferometer. In the double-pulse regime, the longitudinal separation between the pulse pair is made equal to the path length difference of the Franson interferometer. In this paper, we propose another regime by which the generation of time-bin entanglement is possible and demonstrate the scheme experimentally. In our scheme, differently from the previous approaches, the SPDC process is pumped by a cw multi-mode (i.e., short coherence length) laser and makes use of the coherence revival property of such a laser. The high-visibility two-photon Franson interference demonstrates clearly that high-quality time-bin entanglement source can be developed using inexpensive cw multi-mode diode lasers for various quantum communication applications.
Criterion for Bosonic Superfluidity in an Optical Lattice
Diener, Roberto B.; Zhou Qi; Zhai Hui; Ho, T.-L.
2007-05-04
We show that the current method of determining superfluidity in optical lattices based on a visibly sharp bosonic momentum distribution n(k) can be misleading, for even a normal Bose gas can have a similarly sharp n(k). We show that superfluidity in a homogeneous system can be detected from the so-called visibility (v) of n(k)--that v must be 1 within O(N{sup -2/3}), where N is the number of bosons. We also show that the T=0 visibility of trapped lattice bosons is far higher than what is obtained in some current experiments, suggesting strong temperature effects and that these states can be normal. These normal states allow one to explore the physics in the quantum critical region.
Chiral bosonic phases on the Haldane honeycomb lattice
NASA Astrophysics Data System (ADS)
Vasić, Ivana; Petrescu, Alexandru; Le Hur, Karyn; Hofstetter, Walter
2015-03-01
Recent experiments in ultracold atoms and photonic analogs have reported the implementation of artificial gauge fields in lattice systems, facilitating the realization of topological phases. Motivated by such advances, we investigate the Haldane honeycomb lattice tight-binding model, for bosons with local interactions at the average filling of one boson per site. We analyze the ground-state phase diagram and uncover three distinct phases: a uniform superfluid (SF), a chiral superfluid (CSF), and a plaquette Mott insulator with local current loops (PMI). Nearest-neighbor and next-nearest-neighbor currents distinguish CSF from SF, and the phase transition between them is first order. We apply bosonic dynamical mean-field theory and exact diagonalization to obtain the phase diagram, complementing numerics with calculations of excitation spectra in strong and weak coupling perturbation theory. The characteristic density fluctuations, current correlation functions, and excitation spectra are measurable in ultracold atom experiments.
Localized modes in arrays of boson-fermion mixtures
Bludov, Yu. V.; Konotop, V. V.
2006-10-15
It is shown that the mean-field description of a boson-fermion mixture with a dominating fermionic component, loaded in a one-dimensional optical lattice, is reduced to the nonlinear Schroedinger equation with a periodic potential and periodic nonlinearity. In such a system there exist localized modes having peculiar properties. In particular, for some regions of parameters there exists a lower bound for a number of bosons necessary for creation of a mode, while for other domains small amplitude gap solitons are not available in the vicinity of either of the gap edges. We found that the lowest branch of the symmetric solution either does not exist or exists only for a restricted range of energies in a gap, unlike in pure bosonic condensates. The simplest bifurcations of the modes are shown and stability of the modes is verified numerically.
Evolution of 3D Boson Stars with Waveform Extraction
NASA Astrophysics Data System (ADS)
Bondarescu, Ruxandra; Balakrishna, Jayashree; Daues, Gregory; Guzman, Francisco
2005-04-01
This talk will present results from a study of boson stars under nonspherical perturbations using a fully general-relativistic 3D code based on the Cactus Computational Toolkit. We study the evolution of stable, critical and unstable boson stars subjected to various types of nonspherical perturbations and analyze the emitted gravitational waves. We calculate the Zerilli and Newman-Penrose ψ4 gravitational waveforms and study the quasinormal mode content of the numerical waveforms using predicted QNM frequencies from perturbation theory calculations of Yoshida, Eriguchi and Futamase. Our results show that the waveforms accurately display the strong damping predicted for quasinormal modes of boson stars. The apparent horizons formed from perturbed unstable star collapse were observed to be slightly nonspherical when initially detected and became more spherical as the system evolved.
Towards quantum supremacy with lossy scattershot boson sampling
NASA Astrophysics Data System (ADS)
Latmiral, Ludovico; Spagnolo, Nicolò; Sciarrino, Fabio
2016-11-01
Boson sampling represents a promising approach to obtain evidence of the supremacy of quantum systems as a resource for the solution of computational problems. The classical hardness of Boson Sampling has been related to the so called Permanent-of-Gaussians Conjecture and has been extended to some generalizations such as Scattershot Boson Sampling, approximate and lossy sampling under some reasonable constraints. However, it is still unclear how demanding these techniques are for a quantum experimental sampler. Starting from a state of the art analysis and taking account of the foreseeable practical limitations, we evaluate and discuss the bound for quantum supremacy for different recently proposed approaches, accordingly to today’s best known classical simulators.
Quantum field theory for condensation of bosons and fermions
De Souza, Adriano N.; Filho, Victo S.
2013-03-25
In this brief review, we describe the formalism of the quantum field theory for the analysis of the condensation phenomenon in bosonic systems, by considering the cases widely verified in laboratory of trapped gases as condensate states, either with attractive or with repulsive two-body interactions. We review the mathematical formulation of the quantum field theory for many particles in the mean-field approximation, by adopting contact interaction potential. We also describe the phenomenon of condensation in the case of fermions or the degenerate Fermi gas, also verified in laboratory in the crossover BEC-BCS limit. We explain that such a phenomenon, equivalent to the bosonic condensation, can only occur if we consider the coupling of particles in pairs behaving like bosons, as occurs in the case of Cooper's pairs in superconductivity.
Quantum theory of cold bosonic atoms in optical lattices
Tilahun, Dagim; Duine, R. A.; MacDonald, A. H.
2011-09-15
Ultracold atoms in optical lattices undergo a quantum phase transition from a superfluid to a Mott insulator as the lattice potential depth is increased. We describe an approximate theory of interacting bosons in optical lattices which provides a qualitative description of both superfluid and insulator states. The theory is based on a change of variables in which the boson coherent state amplitude is replaced by an effective potential which promotes phase coherence between different number states on each lattice site. It is illustrated here by applying it to uniform and fully frustrated lattice cases but is simple enough that it can be applied to spatially inhomogeneous lattice systems.
Higgs Boson Discovery and Properties
Rowson, Peter C.
2003-06-02
We outline issues examined and progress made by the Light Higgs Snowmass 1996 working group regarding discovering Higgs bosons and measuring their detailed properties. We focused primarily on what could be learned at LEP2, the Tevatron (after upgrade), the LHC, a next linear e{sup +}e{sup -} collider and a {mu}{sup +}{mu}{sup -} collider.
Boson sampling with Gaussian measurements
NASA Astrophysics Data System (ADS)
Chakhmakhchyan, L.; Cerf, N. J.
2017-09-01
We develop an alternative boson sampling model operating on single-photon states followed by linear interferometry and Gaussian measurements. The hardness proof for simulating such continuous-variable measurements is established in two main steps, making use of the symmetry of quantum evolution under time reversal. Namely, we first construct a twofold version of scattershot boson sampling in which, as opposed to the original proposal, both legs of a collection of two-mode squeezed vacuum states undergo parallel linear-optical transformations. This twofold scattershot model yields, as a corollary, an instance of boson sampling from Gaussian states where photon counting is hard to simulate. Then, a time-reversed setup is used to exhibit a boson sampling model in which the simulation of Gaussian measurements—namely the outcome of eight-port homodyne detection—is proven to be computationally hard. These results illustrate how the symmetry of quantum evolution under time reversal may serve as a tool for analyzing the computational complexity of novel physically motivated computational problems.
Microscopic formulation of the interacting boson model for rotational nuclei
Nomura, Kosuke; Shimizu, Noritaka; Otsuka, Takaharu; Guo, Lu
2011-04-15
We propose a novel formulation of the interacting boson model (IBM) for rotational nuclei with axially symmetric, strong deformation. The intrinsic structure represented by the potential-energy surface (PES) of a given multinucleon system has a certain similarity to that of the corresponding multiboson system. Based on this feature, one can derive an appropriate boson Hamiltonian, as already reported. This prescription, however, has a major difficulty in the rotational spectra of strongly deformed nuclei: the bosonic moment of inertia is significantly smaller than the corresponding nucleonic one. We present that this difficulty originates in the difference between the rotational response of a nucleon system and that of the corresponding boson system, and could arise even if the PESs of the two systems were identical. We further suggest that the problem can be solved by implementing the L{center_dot}L term into the IBM Hamiltonian, with the coupling constant derived from the cranking approach of Skyrme mean-field models. The validity of the method is confirmed for rare-earth and actinoid nuclei, as their experimental rotational yrast bands are reproduced nicely.
Paraan, Francis N. C.; Korepin, Vladimir E.; Molina-Vilaplana, Javier; Bose, Sougato
2011-09-15
We quantify the extractable entanglement of excited states of a Lieb-Liniger gas that are obtained from coarse-grained measurements on the ground state in which the boson number in one of two complementary contiguous partitions of the gas is determined. Numerically exact results obtained from the coordinate Bethe ansatz show that the von Neumann entropy of the resulting bipartite pure state increases monotonically with the strength of repulsive interactions and saturates to the impenetrable-boson limiting value. We also present evidence indicating that the largest amount of entanglement can be extracted from the most probable projected state having half the number of bosons in a given partition. Our study points to a fundamental difference between the nature of the entanglement in free-bosonic and free-fermionic systems, with the entanglement in the former being zero after projection, while that in the latter (corresponding to the impenetrable-boson limit) being nonzero.
Higgs mechanism with type-II Nambu-Goldstone bosons at finite chemical potential
Hama, Yusuke; Hatsuda, Tetsuo; Uchino, Shun
2011-06-15
When the spontaneous symmetry breaking occurs for systems without Lorentz covariance, there arises possible mismatch, N{sub NG}
Decoherence and interferometric sensitivity of boson sampling in superconducting resonator networks
NASA Astrophysics Data System (ADS)
Goldstein, Samuel; Korenblit, Simcha; Bendor, Ydan; You, Hao; Geller, Michael R.; Katz, Nadav
2017-01-01
Multiple bosons undergoing coherent evolution in a coupled network of sites constitute a so-called quantum walk system. The simplest example of such a two-particle interference is the celebrated Hong-Ou-Mandel interference. When scaling to larger boson numbers, simulating the exact distribution of bosons has been shown, under reasonable assumptions, to be exponentially hard. We analyze the feasibility and expected performance of a globally connected superconducting resonator based quantum walk system, using the known characteristics of state-of-the-art components. We simulate the sensitivity of such a system to decay processes and to perturbations and compare with coherent input states.
Optical realization of two-boson tunneling dynamics
Longhi, Stefano
2011-04-15
An optical realization of the tunneling dynamics of two interacting bosons in a double-well potential, based on light transport in a four-core microstructured fiber, is proposed. The optical setting enables one to visualize, in a purely classical system, the entire crossover from Rabi oscillations to correlated pair tunneling and to tunneling of a fragmented pair in the fermionization limit.
Fermionized Dipolar Bosons Trapped in a Harmonic Trap
NASA Astrophysics Data System (ADS)
Kościk, Przemysław
2017-03-01
We explore entanglement properties of systems of identical dipolar bosons confined in a 1D harmonic trap by using explicitly correlated Jastrow-type wavefunctions. Results for the linear entropy in dependence on the dimensionless coupling and the number of particles are provided and discussed.
Thermal phase transition for some spin-boson models
NASA Astrophysics Data System (ADS)
Aparicio Alcalde, M.; Pimentel, B. M.
2013-09-01
In this work we study two different spin-boson models. Such models are generalizations of the Dicke model, it means they describe systems of N identical two-level atoms coupled to a single-mode quantized bosonic field, assuming the rotating wave approximation. In the first model, we consider the wavelength of the bosonic field to be of the order of the linear dimension of the material composed of the atoms, therefore we consider the spatial sinusoidal form of the bosonic field. The second model is the Thompson model, where we consider the presence of phonons in the material composed of the atoms. We study finite temperature properties of the models using the path integral approach and functional methods. In the thermodynamic limit, N→∞, the systems exhibit phase transitions from normal to superradiant phase at some critical values of temperature and coupling constant. We find the asymptotic behavior of the partition functions and the collective spectrums of the systems in the normal and the superradiant phases. We observe that the collective spectrums have zero energy values in the superradiant phases, corresponding to the Goldstone mode associated to the continuous symmetry breaking of the models. Our analysis and results are valid in the limit of zero temperature β→∞, where the models exhibit quantum phase transitions.
Phase diagrams of bosonic ABn chains
NASA Astrophysics Data System (ADS)
Cruz, G. J.; Franco, R.; Silva-Valencia, J.
2016-04-01
The A B N - 1 chain is a system that consists of repeating a unit cell with N sites where between the A and B sites there is an energy difference of λ. We considered bosons in these special lattices and took into account the kinetic energy, the local two-body interaction, and the inhomogenous local energy in the Hamiltonian. We found the charge density wave (CDW) and superfluid and Mott insulator phases, and constructed the phase diagram for N = 2 and 3 at the thermodynamic limit. The system exhibited insulator phases for densities ρ = α/ N, with α being an integer. We obtained that superfluid regions separate the insulator phases for densities larger than one. For any N value, we found that for integer densities ρ, the system exhibits ρ + 1 insulator phases, a Mott insulator phase, and ρ CDW phases. For non-integer densities larger than one, several CDW phases appear.
NASA Astrophysics Data System (ADS)
Gao, Zhensen; Sun, Xiao; Zhang, Kaibin
2016-02-01
Wavelength tunable optical transmitter is an essential component for the newly standardized time and wavelength division multiplexed passive optical network (TWDM-PON), where tunable ONU with 10Gb/s bit rate is desired to provide 40Gb/s symmetric bandwidth. In this paper, a novel wavelength tunable optical transmitter is proposed by reusing legacy low speed multi-mode Fabry-Perot laser and connecting it with an integrated photonic chip with two coupled micro-ring resonators to generate a tunable single mode signal based on Vernier effect for 10Gb/s high speed modulation, which makes it as a promising solution for colorless ONU in future symmetric TWDM-PON.
NASA Astrophysics Data System (ADS)
Yadav, Ranvijay; Singh, S. K.; Verma, R. K.; Rai, S. B.
2014-04-01
Micro-crystalline Y2O3 phosphor co-doped with Yb3+/Tm3+ has been synthesized and characterized. The phosphor material gives efficient multimodal emission via downshifting (DS), upconversion (UC), and downconversion (DC)/quantum cutting (QC) luminescence processes. Cross relaxation and co-operative energy transfer (CET) have been ascribed as the possible mechanism for QC; as result of which a UV/blue photon absorbed by Tm3+ splits into two near infrared photons (wavelength range 950-1050 nm) emitted by Yb3+. The Yb3+ concentration dependent ET efficiency and QC efficiency has also been evaluated. Such multi-mode emitting phosphors could have potential applications in increasing the conversion efficiency of solar cells via spectral modification.
NASA Astrophysics Data System (ADS)
Sin, Yongkun; Presser, Nathan; Mason, Maribeth; Moss, Steven C.
2006-02-01
High-power multi-mode broad area InGaAs strained quantum well (QW) single emitters (λ ~ 920-980nm) have been mainly used for industrial applications. Recently, these broad area lasers with CW output powers >5W have also found applications in communications as pump lasers for Er-Yb co-doped fiber amplifiers. This application requires very demanding characteristics including higher reliability than industrial applications. In contrast to 980nm single mode InGaAs strained QW lasers that are widely employed in both terrestrial and submarine applications, the fact that multimode lasers have never been used in optical communications necessitates careful study of these lasers. We report investigations of performance characteristics, reliability, and failure modes of high-power multi-mode single emitters. The lasers studied were broad area strained InGaAs-GaAs single QW lasers grown either by MOCVD or MBE. Typical apertures were around 100μm wide and cavity lengths were <=4.2mm. AR-HR coated laser diode chips were mounted on carriers with junction down configuration to reduce thermal impedance. Laser thresholds were <=453mA at RT. At 6A injection current typical CW output powers were over 5W at 25°C with wall-plug efficiency of ~60%. Characteristics measured included thermal impedance and optical beam profiles that are critical in understanding performance and reliability. Automatic current control burn-in tests with different stress conditions were performed and log (I)-V characteristics were measured at RT to correlate degradation in optical output power and an increase in trap density estimated from the 2κ•T term in bulk recombination current. We also report initial analysis of lifetest results and failure modes from these lasers.
Chiral vortical effect for bosons
NASA Astrophysics Data System (ADS)
Avkhadiev, Artur; Sadofyev, Andrey V.
2017-08-01
The thermal contribution to the chiral vortical effect is believed to be related to the axial anomaly in external gravitational fields. We use the universality of the spin-gravity interaction to extend this idea to a wider set of phenomena. We consider the Kubo formula at weak coupling for the spin current of a vector field and derive a novel anomalous effect caused by the medium rotation: the chiral vortical effect for bosons. The effect consists in a spin current of vector bosons along the angular velocity of the medium. We argue that it has the same anomalous nature as in the fermionic case and show that this effect provides a mechanism for helicity transfer, from flow helicity to magnetic helicity.
Two-dimensional thermofield bosonization
Amaral, R.L.P.G.
2005-12-15
The main objective of this paper was to obtain an operator realization for the bosonization of fermions in 1 + 1 dimensions, at finite, non-zero temperature T. This is achieved in the framework of the real-time formalism of Thermofield Dynamics. Formally, the results parallel those of the T = 0 case. The well-known two-dimensional Fermion-Boson correspondences at zero temperature are shown to hold also at finite temperature. To emphasize the usefulness of the operator realization for handling a large class of two-dimensional quantum field-theoretic problems, we contrast this global approach with the cumbersome calculation of the fermion-current two-point function in the imaginary-time formalism and real-time formalisms. The calculations also illustrate the very different ways in which the transmutation from Fermi-Dirac to Bose-Einstein statistics is realized.
Nonequilibrium Gross-Pitaevskii dynamics of boson lattice models
Polkovnikov, Anatoli; Sachdev, Subir; Girvin, S.M.
2002-11-01
Motivated by recent experiments on trapped ultracold bosonic atoms in an optical lattice potential, we consider the nonequilibrium dynamic properties of such bosonic systems for a number of experimentally relevant situations. When the number of bosons per lattice site is large, there is a wide parameter regime where the effective boson interactions are strong, but the ground state remains a superfluid (and not a Mott insulator): we describe the conditions under which the dynamics in this regime can be described by a discrete Gross-Pitaevskii equation. We describe the evolution of the phase coherence after the system is initially prepared in a Mott insulating state, and then allowed to evolve after a sudden change in parameters places it in a regime with a superfluid ground state. We also consider initial conditions with a '{pi} phase' imprint on a superfluid ground state (i.e., the initial phases of neighboring wells differ by {pi}), and discuss the subsequent appearance of the density wave order and 'Schroedinger cat', i.e., macroscopic quantum interference, states.
Measurements of trilinear gauge boson couplings
Abbott, B.
1997-10-01
Direct measurements of the trilinear gauge boson couplings by the D0 collaboration at Fermilab are reported. Limits on the anomalous couplings were obtained at a 95% CL from four diboson production processes: W{gamma} production with the W boson decaying to e{nu} or {mu}{nu}, WW production with both of the W bosons decaying to e{nu} or {mu}{nu}, WW/WZ production with one W boson decaying to e{nu} and the other W or Z boson decaying to two jets, and Z{gamma} production with the Z boson decaying to ee, {mu}{mu}, or {nu}{nu}. Limits were also obtained from a combined fit to W{gamma}, WW {yields} dileptons and WW/WZ {yields} e{nu}jj data samples.
Bosonization of free Weyl fermions
NASA Astrophysics Data System (ADS)
Marino, E. C.
2017-03-01
We generalize the method of bosonization, in its complete form, to a spacetime with 3 + 1 dimensions, and apply it to free Weyl fermion fields, which thereby, can be expressed in terms of a boson field, namely the Kalb-Ramond anti-symmetric tensor gauge field. The result may have interesting consequences both in condensed matter and in particle physics. In the former, the bosonized form of the Weyl chiral currents provides a simple explanation for the angle-dependent magneto-conductance recently observed in materials known as Weyl semimetals. In the latter, conversely, since electrons can be thought of as a combination of left and right Weyl fermions, our result suggests the possibility of a unified description of the elementary particles, which undergo the fundamental interactions, with the mediators of such interactions, namely, the gauge fields. This would fulfill the pioneering attempt of Skyrme, to unify the particles with their interaction mediators (Skyrme 1962 Nucl. Phys. 31 556).
Fermiophobic Higgs boson and supersymmetry
NASA Astrophysics Data System (ADS)
Gabrielli, E.; Kannike, K.; Mele, B.; Racioppi, A.; Raidal, M.
2012-09-01
If a light Higgs boson with mass 125 GeV is fermiophobic, or partially fermiophobic, then the minimal supersymmetric standard model is excluded. The minimal supersymmetric fermiophobic Higgs scenario can naturally be formulated in the context of the next-to-minimal supersymmetric standard model (NMSSM) that admits Z3 discrete symmetries. In the fermiophobic NMSSM, the supersymmetry naturalness criteria are relaxed by a factor Ncyt4/g4˜25, removing the little hierarchy problem and allowing sparticle masses to be naturally of order 2-3 TeV. This scale motivates wino or Higgsino dark matter. The SUSY flavor and CP problems as well as the constraints on sparticle and Higgs boson masses from b→sγ, Bs→μμ and direct LHC searches are relaxed in the fermiophobic NMSSM. The price to pay is that a new, yet unknown, mechanism must be introduced to generate fermion masses. We show that in the fermiophobic NMSSM the radiative Higgs boson branchings to γγ, γZ can be modified compared to the fermiophobic and ordinary standard model predictions, and fit present collider data better. Suppression of dark matter scattering off nuclei explains the absence of signal in XENON100.
Fat jets for a light higgs boson.
Plehn, Tilman; Salam, Gavin P; Spannowsky, Michael
2010-03-19
At the LHC associated top quark and Higgs boson production with a Higgs boson decay to bottom quarks has long been a heavily disputed search channel. Recently, it has been found not to be viable. We show how it can be observed by tagging massive Higgs bosons and top jets. For this purpose we construct boosted top and Higgs taggers for standard-model processes in a complex QCD environment.
A Search for Dark Higgs Bosons
Lees, J.P.
2012-06-08
Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb{sup -1} of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.
Collider searches for fermiophobic gauge bosons
NASA Astrophysics Data System (ADS)
Bramante, Joseph; Hundi, R. S.; Kumar, Jason; Rajaraman, Arvind; Yaylali, David
2011-12-01
We explore the phenomenology of an extra U(1) gauge boson which primarily couples to standard model gauge bosons. We classify all possible parity-odd couplings up to dimension 6 operators. We then study the prospects for the detection of such a boson at the LHC and show that the electroweak decay channels lead to very clean signals, allowing us to probe couplings well into the TeV scale.
Bloom, Paul Craig
1998-03-01
An investigation of the interactions between the $W$ boson and the $Z$ boson and photon through the pair production of bosons is presented. This has been accomplished via a study of the reaction $p\\overline{p} \\to \\ell\\overline{\
Cold bosons in noisy optical lattices
NASA Astrophysics Data System (ADS)
Schachenmayer, Johannes; Pichler, Hannes; Zoller, Peter; Daley, Andrew
2012-02-01
Cold atoms in optical lattices open the possibility to experimentally study strongly interacting many-body quantum systems with controllable parameters. A key challenge to prepare interesting quantum states in these systems is to achieve sufficiently low temperatures. At these temperatures a deep theoretical understanding of possible heating processes and how they affect the characteristics of the quantum state becomes essential. In every realistic experiment there exist many sources of noise that cause phase and amplitude fluctuations in the standing laser waves that form the optical lattice potential. This classical noise can lead to heating and a significant change of the quantum state. We study the stochastic many-body non-equilibrium dynamics of bosons in an optical lattice and determine how the state changes depending on the characteristics of the noise. We do this by solving time-dependent stochastic many-body Schr"odinger equations, both analytically and numerically.
Rotating boson stars and Q-balls
Kleihaus, Burkhard; Kunz, Jutta; List, Meike
2005-09-15
We consider axially symmetric, rotating boson stars. Their flat-space limits represent spinning Q-balls. We discuss their properties and determine their domain of existence. Q-balls and boson stars are stationary solutions and exist only in a limited frequency range. The coupling to gravity gives rise to a spiral-like frequency dependence of the boson stars. We address the flat-space limit and the limit of strong gravitational coupling. For comparison we also determine the properties of spherically symmetric Q-balls and boson stars.
Bosons, fermions and anyons in the plane, and supersymmetry
Horvathy, Peter A.; Plyushchay, Mikhail S.; Valenzuela, Mauricio
2010-09-15
Universal vector wave equations allowing for a unified description of anyons, and also of usual bosons and fermions in the plane are proposed. The existence of two essentially different types of anyons, based on unitary and also on non-unitary infinite-dimensional half-bounded representations of the (2 + 1)D Lorentz algebra is revealed. Those associated with non-unitary representations interpolate between bosons and fermions. The extended formulation of the theory includes the previously known Jackiw-Nair (JN) and Majorana-Dirac (MD) descriptions of anyons as particular cases, and allows us to compose bosons and fermions from entangled anyons. The theory admits a simple supersymmetric generalization, in which the JN and MD systems are unified in N = 1 and N = 2 supermultiplets. Two different non-relativistic limits of the theory are investigated. The usual one generalizes Levy-Leblond's spin 1/2 theory to arbitrary spin, as well as to anyons. The second, 'Jackiw-Nair' limit (that corresponds to Inoenue-Wigner contraction with both anyon spin and light velocity going to infinity), is generalized to boson/fermion fields and interpolating anyons. The resulting exotic Galilei symmetry is studied in both the non-supersymmetric and supersymmetric cases.
Superfluidity of bosons in kagome lattices with frustration.
You, Yi-Zhuang; Chen, Zhu; Sun, Xiao-Qi; Zhai, Hui
2012-12-28
In this Letter we consider spinless bosons in a kagome lattice with nearest-neighbor hopping and on-site interaction, and the sign of hopping is inverted by insetting a π flux in each triangle of the kagome lattice so that the lowest single particle band is perfectly flat. We show that in the high-density limit, despite the infinite degeneracy of the single particle ground states, interaction will select out the Bloch state at the K point of the Brillouin zone for boson condensation at the lowest temperature. As the temperature increases, the single-boson superfluid order can be easily destroyed, while an exotic triple-boson paired superfluid order will remain. We establish that this trion superfluid exists in a broad temperature regime until the temperature is increased to the same order of hopping and then the system turns into normal phases. Finally, we show that time-of-flight measurement of the momentum distribution and its noise correlation can be used to distinguish these three phases.
ERIC Educational Resources Information Center
Baar, Marsha R.; Gammerdinger, William; Leap, Jennifer; Morales, Erin; Shikora, Jonathan; Weber, Michael H.
2014-01-01
Five reactions were rate-accelerated relative to the standard reflux workup in both multi-mode and mono-mode microwave ovens, and the results were compared to determine whether the sequential processing of a mono-mode unit could provide for better lab logistics and pedagogy. Conditions were optimized so that yields matched in both types of…
ERIC Educational Resources Information Center
Baar, Marsha R.; Gammerdinger, William; Leap, Jennifer; Morales, Erin; Shikora, Jonathan; Weber, Michael H.
2014-01-01
Five reactions were rate-accelerated relative to the standard reflux workup in both multi-mode and mono-mode microwave ovens, and the results were compared to determine whether the sequential processing of a mono-mode unit could provide for better lab logistics and pedagogy. Conditions were optimized so that yields matched in both types of…
NASA Astrophysics Data System (ADS)
Takemoto, Takashi; Yamashita, Hiroki; Matsuoka, Yasunobu; Adachi, Koichiro; Lee, Yong
2014-02-01
A 1.3-μm wavelength optical link, which consists of a lens-integrated laser diode and a CMOS optical receiver, was developed. It achieves 25-Gb/s error-free 100-m multi-mode fiber transmission with sensitivity of -6.3-dBm OMA.
Batalin-Fradkin-Tyutin embedding of noncommutative chiral bosons
Kim, Wontae; Park, Young-Jai; Shin, Hyeonjoon; Yoon, Myung Seok
2007-04-15
A two dimensional model of chiral bosons in noncommutative field space is considered in the framework of the Batalin-Fradkin-Tyutin Hamiltonian embedding method converting the second-class constrained system into the first-class one. The symmetry structure associated with the first-class constraints is explored and the propagation speed of fields is equivalent to that of the second-class constraint system.
Information Transmission and Entanglement Distribution Over Bosonic Channels
2008-03-01
communication systems have seldom employed fully quantum treatments. As a result, these works do not establish the ultimate limits on optical ...High-sensitivity photodetection systems have long been limited by noises of quantum-mechanical origin. Nevertheless, analyses and designs of optical ... communication performance. This program established an inner bound on the capacity region for the Bosonic broadcast channel, and showed that this inner bound
Huh, Joonsuk; Yung, Man-Hong
2017-08-07
Molecular vibroic spectroscopy, where the transitions involve non-trivial Bosonic correlation due to the Duschinsky Rotation, is strongly believed to be in a similar complexity class as Boson Sampling. At finite temperature, the problem is represented as a Boson Sampling experiment with correlated Gaussian input states. This molecular problem with temperature effect is intimately related to the various versions of Boson Sampling sharing the similar computational complexity. Here we provide a full description to this relation in the context of Gaussian Boson Sampling. We find a hierarchical structure, which illustrates the relationship among various Boson Sampling schemes. Specifically, we show that every instance of Gaussian Boson Sampling with an initial correlation can be simulated by an instance of Gaussian Boson Sampling without initial correlation, with only a polynomial overhead. Since every Gaussian state is associated with a thermal state, our result implies that every sampling problem in molecular vibronic transitions, at any temperature, can be simulated by Gaussian Boson Sampling associated with a product of vacuum modes. We refer such a generalized Gaussian Boson Sampling motivated by the molecular sampling problem as Vibronic Boson Sampling.
Droplets of Trapped Quantum Dipolar Bosons
NASA Astrophysics Data System (ADS)
Macia, A.; Sánchez-Baena, J.; Boronat, J.; Mazzanti, F.
2016-11-01
Strongly interacting systems of dipolar bosons in three dimensions confined by harmonic traps are analyzed using the exact path integral ground-state Monte Carlo method. By adding a repulsive two-body potential, we find a narrow window of interaction parameters leading to stable ground-state configurations of droplets in a crystalline arrangement. We find that this effect is entirely due to the interaction present in the Hamiltonian without resorting to additional stabilizing mechanisms or specific three-body forces. We analyze the number of droplets formed in terms of the Hamiltonian parameters, relate them to the corresponding s -wave scattering length, and discuss a simple scaling model for the density profiles. Our results are in qualitative agreement with recent experiments showing a quantum Rosensweig instability in trapped Dy atoms.
Strong correlations in bosons and fermions
NASA Astrophysics Data System (ADS)
Tilahun, Dagim
If there is a general theme to this thesis, it is the effects of strong correlations in both bosons and fermions. The bosonic system considered here consists of ultracold alkali atoms trapped by interfering lasers, so called optical lattices. Strong interactions, realized by increasing the depth of the lattice potential, or through the phenomenon of Feshbach resonances induce strong correlations amongst the atoms, rendering attempts to describe the systems in terms of single particle type physics unsuccessful. Of course strong correlations are not the exclusive domain of bosons, and also are not caused only by strong interactions. Other factors such as reduced dimensionality, in one-dimensional electron gases, or strong magnetic fields, in two-dimensional electron gases are known to induce strong correlations. In this thesis, we explore the manifestations of strong correlations in ultracold atoms in optical lattices and interacting electron gases. Optical lattices provide a near-perfect realization of lattice models, such as the bosonic Hubbard model (BHM) that have been formulated to study solid state systems. This follows from the absence of defects or impurities that usually plague real solid state systems. Another novel feature of optical lattices is the unprecedented control experimenters have in tuning the different lattice parameters, such as the lattice spacing and the intensity of the lasers. This control enables one to study the model Hamiltonians over a wide range of variables, such as the interaction strength between the atoms, thereby opening the door towards the observation of diverse and interesting phenomena. The BHM, and also its variants, predict various quantum phases, such as the strongly correlated Mott insulator (MI) phase that appears as a function of the parameter t/U, the ratio of the nearest neighbor hopping amplitude to the on-site interaction, which one varies experimentally over a wide range of values simply by switching the intensity
Goldstone bosons as fractional cosmic neutrinos.
Weinberg, Steven
2013-06-14
It is suggested that Goldstone bosons may be masquerading as fractional cosmic neutrinos, contributing about 0.39 to what is reported as the effective number of neutrino types in the era before recombination. The broken symmetry associated with these Goldstone bosons is further speculated to be the conservation of the particles of dark matter.
Higgs Boson Mass, Neutrino Oscillations and Inflation
Shafi, Qaisar
2008-11-23
Finding the Standard Model scalar (Higgs) boson is arguably the single most important mission of the LHC. I review predictions for the Higgs boson mass based on stability and perturbativity arguments, taking into account neutrino oscillations. Primordial inflation based on the Coleman-Weinberg potential is briefly discussed.
Superalgebra and fermion-boson symmetry
Miyazawa, Hironari
2010-01-01
Fermions and bosons are quite different kinds of particles, but it is possible to unify them in a supermultiplet, by introducing a new mathematical scheme called superalgebra. In this article we discuss the development of the concept of symmetry, starting from the rotational symmetry and finally arriving at this fermion-boson (FB) symmetry. PMID:20228617
Higgs Boson Mass, New Physics and Inflation
Shafi, Qaisar
2008-05-13
Finding the Standard Model scalar (Higgs) boson is arguably the single most important mission of the LHC. I review predictions for the Higgs boson mass based on stability and perturbativity arguments, taking into account neutrino oscillations. Other topics that are briefly discussed include the CMSSM, extra dimensions, higher dimensional orbifold GUTS, and primordial inflation based on the Coleman-Weinberg potential.
Higgs bosons in standard model extensions
NASA Astrophysics Data System (ADS)
Gurskaya, A. V.; Dolgopolov, M. V.; Rykova, E. N.
2017-09-01
Several possibilities for extending the scalar sector of the Standard Model are considered. The conditions of calculation of Higgs bosons masses in the Next-to-Minimal Supersymmetric Standard Model are discussed. The probable limits on mass parameters of Higgs bosons are analyzed. The role of minimum conditions as a physical criterion in a model with an extended scalar sector is defined.
Higgs boson couplings: Measurements and theoretical interpretation
NASA Astrophysics Data System (ADS)
Mariotti, Chiara; Passarino, Giampiero
2017-02-01
This report will review the Higgs boson properties: the mass, the total width and the couplings to fermions and bosons. The measurements have been performed with the data collected in 2011 and 2012 at the LHC accelerator at CERN by the ATLAS and CMS experiments. Theoretical frameworks to search for new physics are also introduced and discussed.
Degradability of Bosonic Gaussian channels
Caruso, Filippo; Giovannetti, Vittorio
2006-12-15
The notion of weak-degradability of quantum channels is introduced by generalizing the degradability definition given by Devetak and Shor. Exploiting the unitary equivalence with beam-splitter/amplifier channels we then prove that a large class of one-mode Bosonic Gaussian channels are either weakly degradable or anti-degradable. In the latter case this implies that their quantum capacity Q is null. In the former case instead, this allows us to establish the additivity of the coherent information for those maps which admit unitary representation with single-mode pure environment.
Quantum distillation of bosons
NASA Astrophysics Data System (ADS)
Weiss, David
2015-05-01
The non-equilibrium dynamics of many-body quantum systems present a series of challenges for theory and opportunities for cold atom experiments. I will describe an experiment in which a bundle of initially trapped superfluid 1D Bose lattice gases is quenched to an untrapped, flat lattice potential. This simple experimental situation in the intermediate coupling regime (U/J between 4 and 9.6) leads to interesting dynamics. These include the progressive dissolution of a fraction of the doublons, as well as the quantum distillation and long term confinement of singlons out of and within the central, doublon-dominated region. We measure these processes by combining absorption imaging, photoassociation and 3-body loss to separately reconstruct the spatial distributions of the expectation values of singlons, doublons and triplons. The qualitative dynamics is reproduced by a Gutzwiller mean field model and the essence of the experiment can be understood by considering simple spatial pictures of site occupancies. This work was supported by the NSF and the ARO.
Proton-neutron interacting boson model under random two-body interactions
Yoshida, N.; Zhao, Y. M.; Arima, A.
2009-12-15
The low-lying states of sd-boson systems in the presence of random two-body interactions are studied in the proton-neutron interacting boson model (IBM-2). The predominance of spin-zero ground states is confirmed, and a very prominent maximum F-spin dominance in ground states is found. It turns out that the requirement of random interactions with F-spin conservation intensifies the above predominance. Collective motion in the low-lying states is discussed.
The Boson peak in supercooled water
Kumar, Pradeep; Wikfeldt, K. Thor; Schlesinger, Daniel; Pettersson, Lars G. M.; Stanley, H. Eugene
2013-01-01
We perform extensive molecular dynamics simulations of the TIP4P/2005 model of water to investigate the origin of the Boson peak reported in experiments on supercooled water in nanoconfined pores, and in hydration water around proteins. We find that the onset of the Boson peak in supercooled bulk water coincides with the crossover to a predominantly low-density-like liquid below the Widom line TW. The frequency and onset temperature of the Boson peak in our simulations of bulk water agree well with the results from experiments on nanoconfined water. Our results suggest that the Boson peak in water is not an exclusive effect of confinement. We further find that, similar to other glass-forming liquids, the vibrational modes corresponding to the Boson peak are spatially extended and are related to transverse phonons found in the parent crystal, here ice Ih. PMID:23771033
Search for new heavy charged gauge bosons
Magass, Carsten Martin
2007-11-02
Additional gauge bosons are introduced in many theoretical extensions to the Standard Model. A search for a new heavy charged gauge boson W' decaying into an electron and a neutrino is presented. The data used in this analysis was taken with the D0 detector at the Fermilab proton-antiproton collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of about 1 fb^{-1}. Since no significant excess is observed in the data, an upper limit is set on the production cross section times branching fraction σ_{W'}xBr (W' → ev). Using this limit, a W' boson with mass below ~1 TeV can be excluded at the 95% confidence level assuming that the new boson has the same couplings to fermions as the Standard Model W boson.
Chiral bosonization for non-commutative fields
NASA Astrophysics Data System (ADS)
Das, Ashok; Gamboa, J.; Méndez, Fernando; López-Sarrión, Justo
2004-05-01
A model of chiral bosons on a non-commutative field space is constructed and new generalized bosonization (fermionization) rules for these fields are given. The conformal structure of the theory is characterized by a level of the Kac-Moody algebra equal to (1+theta2) where theta is the non-commutativity parameter and chiral bosons living in a non-commutative fields space are described by a rational conformal field theory with the central charge of the Virasoro algebra equal to 1. The non-commutative chiral bosons are shown to correspond to a free fermion moving with a speed equal to c' = c(1+theta2)1/2 where c is the speed of light. Lorentz invariance remains intact if c is rescaled by crightarrowc'. The dispersion relation for bosons and fermions, in this case, is given by omega = c'|k|.
Spherical boson stars as black hole mimickers
Guzman, F. S.; Rueda-Becerril, J. M.
2009-10-15
We present spherically symmetric boson stars as black hole mimickers based on the power spectrum of a simple accretion disk model. The free parameters of the boson star are the mass of the boson and the fourth-order self-interaction coefficient in the scalar field potential. We show that even if the mass of the boson is the only free parameter, it is possible to find a configuration that mimics the power spectrum of the disk due to a black hole of the same mass. We also show that for each value of the self-interaction a single boson star configuration can mimic a black hole at very different astrophysical scales in terms of the mass of the object and the accretion rate. In order to show that it is possible to distinguish one of our mimickers from a black hole, we also study the deflection of light.
Emerging bosons with three-body interactions from spin-1 atoms in optical lattices
Mazza, L.; Rizzi, M.; Cirac, J. I.; Lewenstein, M.
2010-10-15
We study two many-body systems of bosons interacting via an infinite three-body contact repulsion in a lattice: a pairs quasicondensate induced by correlated hopping and the discrete version of the Pfaffian wave function. We propose to experimentally realize systems characterized by such interaction by means of a proper spin-1 lattice Hamiltonian: spin degrees of freedom are locally mapped into occupation numbers of emerging bosons, in a fashion similar to spin-1/2 and hardcore bosons. Such a system can be realized with ultracold spin-1 atoms in a Mott insulator with a filling factor of 1. The high versatility of these setups allows us to engineer spin-hopping operators breaking the SU(2) symmetry, as needed to approximate interesting bosonic Hamiltonians with three-body hardcore constraint. For this purpose we combine bichromatic spin-independent superlattices and Raman transitions to induce a different hopping rate for each spin orientation. Finally, we illustrate how our setup could be used to experimentally realize the first setup, that is, the transition to a pairs quasicondensed phase of the emerging bosons. We also report on a route toward the realization of a discrete bosonic Pfaffian wave function and list some open problems for reaching this goal.
Bosonic pair creation and the Schiff-Snyder-Weinberg effect
NASA Astrophysics Data System (ADS)
Lv, Q. Z.; Bauke, Heiko; Su, Q.; Keitel, C. H.; Grobe, R.
2016-01-01
Interactions between different bound states in bosonic systems can lead to pair creation. We study this process in detail by solving the Klein-Gordon equation on space-time grids in the framework of time-dependent quantum field theory. By choosing specific external field configurations, two bound states can become pseudodegenerate, which is commonly referred to as the Schiff-Snyder-Weinberg effect. These pseudodegenerate bound states, which have complex energy eigenvalues, are related to the pseudo-Hermiticity of the Klein-Gordon Hamiltonian. In this work, the influence of the Schiff-Snyder-Weinberg effect on pair production is studied. A generalized Schiff-Snyder-Weinberg effect, where several pairs of pseudodegenerate states appear, is found in combined electric and magnetic fields. The generalized Schiff-Snyder-Weinberg effect likewise triggers pair creation. The particle number in these situations obeys an exponential growth law in time enhancing the creation of bosons, which cannot be found in fermionic systems.
2015-11-23
Among others, examples in- clude tolerances of the values of the capacitor, the dielectric constant, and the loss of the substrate as well as...Romeu, “Optimum antenna matching to minimise signal correlation on a two-port antenna diversity system,” Electron. Lett., vol. 40, no. 19, pp. 1164–1165...Electromagn. Res. Lett., vol. 37, pp. 133–142, 2013. [17] H. Li, X. Lin, B. K. Lau, and S. He, “Equivalent circuit based calculation of signal correlation
Mixture of interacting supersymmetric spinless fermions and bosons in a one-dimensional trap
NASA Astrophysics Data System (ADS)
Schlottmann, P.
2016-09-01
We consider a gas mixture consisting of spinless fermions and bosons in one dimension interacting via a repulsive δ-function potential. Bosons and fermions are assumed to have equal masses and the interaction strength between bosons and among bosons and fermions is the same. Using the Bethe ansatz solution of the model, we study the ground state properties, the dressed energy potentials for the two bands of rapidities, the elementary particle and hole excitations, the thermodynamics, the finite size corrections to the ground state energy leading to the conformal towers, and the asymptotic behavior at large distances of some relevant correlation functions. The low-energy excitations of the system form a two-component Luttinger liquid. In an elongated optical trap the gas phase separates as a function of the distance from the center of the trap.
Carvalho, N. C. Le Floch, J-M.; Tobar, M. E.; Krupka, J.
2015-05-11
The Y{sub 2}SiO{sub 5} (YSO) crystal is a dielectric material with biaxial anisotropy with known values of refractive index at optical frequencies. It is a well-known rare-earth (RE) host material for optical research and more recently has shown promising performance for quantum-engineered devices. In this paper, we report the first microwave characterization of the real permittivity tensor of a bulk YSO sample, as well as an investigation of the temperature dependence of the tensor components from 296 K down to 6 K. Estimated uncertainties were below 0.26%, limited by the precision of machining the cylindrical dielectric. Also, the electrical Q-factors of a few electromagnetic modes were recorded as a way to provide some information about the crystal losses over the temperature range. To solve the tensor components necessary for a biaxial crystal, we developed the multi-mode technique, which uses simultaneous measurement of low order whispering gallery modes. Knowledge of the permittivity tensor offers important data, essential for the design of technologies involving YSO, such as microwave coupling to electron and hyperfine transitions in RE doped samples at low temperatures.
Multi-mode technique for the determination of the biaxial Y2SiO5 permittivity tensor from 300 to 6 K
NASA Astrophysics Data System (ADS)
Carvalho, N. C.; Le Floch, J.-M.; Krupka, J.; Tobar, M. E.
2015-05-01
The Y2SiO5 (YSO) crystal is a dielectric material with biaxial anisotropy with known values of refractive index at optical frequencies. It is a well-known rare-earth (RE) host material for optical research and more recently has shown promising performance for quantum-engineered devices. In this paper, we report the first microwave characterization of the real permittivity tensor of a bulk YSO sample, as well as an investigation of the temperature dependence of the tensor components from 296 K down to 6 K. Estimated uncertainties were below 0.26%, limited by the precision of machining the cylindrical dielectric. Also, the electrical Q-factors of a few electromagnetic modes were recorded as a way to provide some information about the crystal losses over the temperature range. To solve the tensor components necessary for a biaxial crystal, we developed the multi-mode technique, which uses simultaneous measurement of low order whispering gallery modes. Knowledge of the permittivity tensor offers important data, essential for the design of technologies involving YSO, such as microwave coupling to electron and hyperfine transitions in RE doped samples at low temperatures.
Klein, R.I. |; Bell, J.; Pember, R.; Kelleher, T.
1993-04-01
The authors present results for high resolution hydrodynamic calculations of the growth and development of instabilities in shock driven imploding spherical geometries in both 2D and 3D. They solve the Eulerian equations of hydrodynamics with a high order Godunov approach using local adaptive mesh refinement to study the temporal and spatial development of the turbulent mixing layer resulting from both Richtmyer Meshkov and Rayleigh Taylor instabilities. The use of a high resolution Eulerian discretization with adaptive mesh refinement permits them to study the detailed three-dimensional growth of multi-mode perturbations far into the non-linear regime for converging geometries. They discuss convergence properties of the simulations by calculating global properties of the flow. They discuss the time evolution of the turbulent mixing layer and compare its development to a simple theory for a turbulent mix model in spherical geometry based on Plesset`s equation. Their 3D calculations show that the constant found in the planar incompressible experiments of Read and Young`s may not be universal for converging compressible flow. They show the 3D time trace of transitional onset to a mixing state using the temporal evolution of volume rendered imaging. Their preliminary results suggest that the turbulent mixing layer loses memory of its initial perturbations for classical Richtmyer Meshkov and Rayleigh Taylor instabilities in spherically imploding shells. They discuss the time evolution of mixed volume fraction and the role of vorticity in converging 3D flows in enhancing the growth of a turbulent mixing layer.
Williams, Brad J; Ciavarini, Steve J; Devlin, Curt; Cohn, Steven M; Xie, Rong; Vissers, Johannes P C; Martin, LeRoy B; Caswell, Allen; Langridge, James I; Geromanos, Scott J
2016-08-01
In proteomics studies, it is generally accepted that depth of coverage and dynamic range is limited in data-directed acquisitions. The serial nature of the method limits both sensitivity and the number of precursor ions that can be sampled. To that end, a number of data-independent acquisition (DIA) strategies have been introduced with these methods, for the most part, immune to the sampling issue; nevertheless, some do have other limitations with respect to sensitivity. The major limitation with DIA approaches is interference, i.e., MS/MS spectra are highly chimeric and often incapable of being identified using conventional database search engines. Utilizing each available dimension of separation prior to ion detection, we present a new multi-mode acquisition (MMA) strategy multiplexing both narrowband and wideband DIA acquisitions in a single analytical workflow. The iterative nature of the MMA workflow limits the adverse effects of interference with minimal loss in sensitivity. Qualitative identification can be performed by selected ion chromatograms or conventional database search strategies.
Has the Higgs boson been discovered?
Renton, Peter
2004-03-11
The standard model of particle physics describes the strong and electroweak interactions of fermions (spin-1/2), gauge bosons (spin-1) and a final vital ingredient--the spin-0 Higgs boson, which gives masses to the other particles. But the Higgs boson has yet to be discovered, and its own mass is not specified by the theory. There is some evidence (although statistically not very significant) for its detection at a mass of about 115 GeV/c2, from electron-positron interactions at LEP (the Large Electron Positron collider). Indirect methods can also be used to constrain the mass of the Higgs boson, because it affects other observable quantities (for example, the mass of the W boson and some measurable properties of the Z boson). An indirect determination of the Higgs boson mass from the most recent measurements of such quantities yields a value compatible with 115 GeV/c2, but with some important caveats arising from inconsistencies in the present data.
NLO Vector Boson Production With Light Jets
Bern, Z.; Diana, G.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Hoeche, S.; Ita, H.; Kosower, D.A.; Maitre, D.; Ozeren, K.
2012-02-15
In this contribution we present recent progress in the computation of next-to-leading order (NLO) QCD corrections for the production of an electroweak vector boson in association with jets at hadron colliders. We focus on results obtained using the virtual matrix element library BlackHat in conjunction with SHERPA, focusing on results relevant to understanding the background to top production. The production of a vector boson in association with several jets at the Large Hadron Collider (LHC) is an important background for other Standard Model processes as well as new physics signals. In particular, the production of a W boson in association with many jets is an important background for processes involving one or more top quarks. Precise predictions for the backgrounds are crucial to measurement of top-quark processes. Vector boson production in association with multiple jets is also a very important background for many SUSY searches, as it mimics the signatures of many typical decay chains. Here we will discuss how polarization information can be used as an additional handle to differentiate top pair production from 'prompt' W-boson production. More generally, ratios of observables, for example for events containing a W boson versus those containing a Z boson, are expected to be better-behaved as many uncertainties cancel in such ratios. Precise calculation of ratios, along with measurement of one of the two processes in the ratio, can be used in data-driven techniques for estimating backgrounds.
Final fate of compact boson star mergers
NASA Astrophysics Data System (ADS)
Bezares, Miguel; Palenzuela, Carlos; Bona, Carles
2017-06-01
Boson stars, self-gravitating objects made of a complex scalar field, have been proposed as simple models for very different scenarios, ranging from galaxy dark matter to black hole mimickers. Here we focus on a very compact type of boson stars to study binary mergers by varying different parameters, namely the phase shift, the direction of rotation, and the angular momentum. Our aim is to investigate the properties of the object resulting from the merger in these different scenarios by means of numerical evolutions. These simulations, performed by using a modification of the covariant conformal Z4 formalism of the Einstein equations that does not require the algebraic enforcing of any constraint, indicate that the final state after a head-on collision of low mass boson stars is another boson star. However, almost complete annihilation of the stars occurs during the merger of a boson-antiboson pair. The merger of orbiting boson stars form a rotating bar that quickly relaxes to a nonrotating boson star.
Rupin, Matthieu; Roux, Philippe; Lerosey, Geoffroy; Lemoult, Fabrice
2015-01-01
Locally resonant metamaterials derive their effective properties from hybridization between their resonant unit cells and the incoming wave. This phenomenon is well understood in the case of plane waves that propagate in media where the unit cell respects the symmetry of the incident field. However, in many systems, several modes with orthogonal symmetries can coexist at a given frequency, while the resonant unit cells themselves can have asymmetric scattering cross-sections. In this paper we are interested in the influence of symmetry breaking on the hybridization of a wave field that includes multiple propagative modes. The A0 and S0 Lamb waves that propagate in a thin plate are good candidates for this study, as they are either anti-symmetric or symmetric. First we designed an experimental setup with an asymmetric metamaterial made of long rods glued to one side of a metallic plate. We show that the flexural resonances of the rods induce a break of the orthogonality between the A0/S0 modes of the free-plate. Finally, based on numerical simulations we show that the orthogonality is preserved in the case of a symmetric metamaterial leading to the presence of two independent polariton curves in the dispersion relation. PMID:26333601
Rupin, Matthieu; Roux, Philippe; Lerosey, Geoffroy; Lemoult, Fabrice
2015-09-03
Locally resonant metamaterials derive their effective properties from hybridization between their resonant unit cells and the incoming wave. This phenomenon is well understood in the case of plane waves that propagate in media where the unit cell respects the symmetry of the incident field. However, in many systems, several modes with orthogonal symmetries can coexist at a given frequency, while the resonant unit cells themselves can have asymmetric scattering cross-sections. In this paper we are interested in the influence of symmetry breaking on the hybridization of a wave field that includes multiple propagative modes. The A0 and S0 Lamb waves that propagate in a thin plate are good candidates for this study, as they are either anti-symmetric or symmetric. First we designed an experimental setup with an asymmetric metamaterial made of long rods glued to one side of a metallic plate. We show that the flexural resonances of the rods induce a break of the orthogonality between the A0/S0 modes of the free-plate. Finally, based on numerical simulations we show that the orthogonality is preserved in the case of a symmetric metamaterial leading to the presence of two independent polariton curves in the dispersion relation.
NASA Astrophysics Data System (ADS)
Rupin, Matthieu; Roux, Philippe; Lerosey, Geoffroy; Lemoult, Fabrice
2015-09-01
Locally resonant metamaterials derive their effective properties from hybridization between their resonant unit cells and the incoming wave. This phenomenon is well understood in the case of plane waves that propagate in media where the unit cell respects the symmetry of the incident field. However, in many systems, several modes with orthogonal symmetries can coexist at a given frequency, while the resonant unit cells themselves can have asymmetric scattering cross-sections. In this paper we are interested in the influence of symmetry breaking on the hybridization of a wave field that includes multiple propagative modes. The A0 and S0 Lamb waves that propagate in a thin plate are good candidates for this study, as they are either anti-symmetric or symmetric. First we designed an experimental setup with an asymmetric metamaterial made of long rods glued to one side of a metallic plate. We show that the flexural resonances of the rods induce a break of the orthogonality between the A0/S0 modes of the free-plate. Finally, based on numerical simulations we show that the orthogonality is preserved in the case of a symmetric metamaterial leading to the presence of two independent polariton curves in the dispersion relation.
Stringent and Efficient Assessment of Boson-Sampling Devices
NASA Astrophysics Data System (ADS)
Tichy, Malte C.; Mayer, Klaus; Buchleitner, Andreas; Mølmer, Klaus
2014-07-01
Boson sampling holds the potential to experimentally falsify the extended Church-Turing thesis. The computational hardness of boson sampling, however, complicates the certification that an experimental device yields correct results in the regime in which it outmatches classical computers. To certify a boson sampler, one needs to verify quantum predictions and rule out models that yield these predictions without true many-boson interference. We show that a semiclassical model for many-boson propagation reproduces coarse-grained observables that are proposed as witnesses of boson sampling. A test based on Fourier matrices is demonstrated to falsify physically plausible alternatives to coherent many-boson propagation.
Method and apparatus for operating a powertrain system upon detecting a stuck-closed clutch
Hansen, R. Anthony
2014-02-18
A powertrain system includes a multi-mode transmission having a plurality of torque machines. A method for controlling the powertrain system includes identifying all presently applied clutches including commanded applied clutches and the stuck-closed clutch upon detecting one of the torque-transfer clutches is in a stuck-closed condition. A closed-loop control system is employed to control operation of the multi-mode transmission accounting for all the presently applied clutches.
Higgs Boson Property Shifts from Radion Mixing
Rizzo, Thomas G.
2002-07-09
We discuss how mixing between the Standard Model Higgs boson, h, and the radion of the Randall-Sundrum model can lead to significant shifts in the expected properties of the Higgs boson. In particular we show that the total and partial decay widths of the Higgs, as well as the h {yields} gg branching fraction, can be substantially altered from their SM expectations, while the remaining branching fractions are modified less than {approx}< 5% for most of the parameter space volume. Precision measurements of Higgs boson properties at a Linear Collider are shown to probe a large region of the Randall-Sundrum model parameter space.
Higgs boson at LHC: a diffractive opportunity
Ducati, M. B. Gay; Silveira, G. G.
2009-03-23
An alternative process is presented for diffractive Higgs boson production in peripheral pp collisions, where the particles interact through the Double Pomeron Exchange. The event rate is computed as a central-rapidity distribution for Tevatron and LHC energies leading to a result around 0.6 pb, higher than the predictions from previous approaches. Therefore, this result arises as an enhanced signal for the detection of the Higgs boson in hadron colliders. The predictions for the Higgs boson photoproduction are compared to the ones obtained from a similar approach proposed by the Durham group, enabling an analysis of the future developments of its application to pp and AA collisions.
Boson formulation of fermion field theories
Ha, Y.K.
1984-04-15
The nonperturbative connection between a canonical Fermi field and a canonical Bose field in two dimensions is developed and its validity verified according to the tenets of quantum field theory. We advocate the point of view that a boson formulation offers a unifying theme in understanding the structure of many theories. This is illustrated by the boson formulation of a multifermion theory with chiral and internal symmetries. Many features of the massless theory, such as dynamical mass generation with asymptotic-freedom behavior, hidden chiral symmetry, and connections with models of apparently different internal symmetries, are readily transparent through such fermion-boson metamorphosis.
Three-dimensional topological insulators and bosonization
NASA Astrophysics Data System (ADS)
Cappelli, Andrea; Randellini, Enrico; Sisti, Jacopo
2017-05-01
Massless excitations at the surface of three-dimensional time-reversal invariant topological insulators possess both fermionic and bosonic descriptions, originating from band theory and hydrodynamic BF theory, respectively. We analyze the corresponding field theories of the Dirac fermion and compactified boson and compute their partition functions on the three-dimensional torus geometry. We then find some non-dynamic exact properties of bosonization in (2+1) dimensions, regarding fermion parity and spin sectors. Using these results, we extend the Fu-Kane-Mele stability argument to fractional topological insulators in three dimensions.
Interacting Boson Problems Can Be QMA Hard
NASA Astrophysics Data System (ADS)
Wei, Tzu-Chieh; Mosca, Michele; Nayak, Ashwin
2010-01-01
Computing the ground-state energy of interacting electron problems has recently been shown to be hard for quantum Merlin Arthur (QMA), a quantum analogue of the complexity class NP. Fermionic problems are usually hard, a phenomenon widely attributed to the so-called sign problem. The corresponding bosonic problems are, according to conventional wisdom, tractable. Here, we demonstrate that the complexity of interacting boson problems is also QMA hard. Moreover, the bosonic version of N-representability problem is QMA complete. Consequently, these problems are unlikely to have efficient quantum algorithms.
Measurement of the W Boson Mass
NASA Astrophysics Data System (ADS)
Abachi, S.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alitti, J.; Álvarez, G.; Alves, G. A.; Amidi, E.; Amos, N.; Anderson, E. W.; Aronson, S. H.; Astur, R.; Avery, R. E.; Baarmand, M. M.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Bartlett, J. F.; Bazizi, K.; Belyaev, A.; Bendich, J.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Bischoff, A.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Borders, J.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; de, K.; Demarteau, M.; Denisenko, N.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Dixon, R.; Draper, P.; Drinkard, J.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahey, S.; Fahland, T.; Fatyga, M.; Fatyga, M. K.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Franzini, P.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Geld, T. L.; Genik, R. J., II; Genser, K.; Gerber, C. E.; Gibbard, B.; Glebov, V.; Glenn, S.; Glicenstein, J. F.; Gobbi, B.; Goforth, M.; Goldschmidt, A.; Gómez, B.; Gomez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Griffin, G.; Grossman, N.; Grudberg, P.; Grünendahl, S.; Gu, W. X.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Guryn, W.; Gurzhiev, S. N.; Gutierrez, P.; Gutnikov, Y. E.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hansen, S.; Hatcher, R.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Tao; Hu, Ting; Hu, Tong; Huehn, T.; Igarashi, S.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johari, H.; Johns, K.; Johnson, M.; Johnstad, H.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Kehoe, R.; Kelly, M. L.; Kerth, L.; Kim, C. L.; Kim, S. K.; Klatchko, A.; Klima, B.; Klochkov, B. I.; Klopfenstein, C.; Klyukhin, V. I.; Kochetkov, V. I.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kourlas, J.; Kozelov, A. V.; Kozlovski, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Landsberg, G.; Lauer, B.; Lebrat, J.-F.; Leflat, A.; Li, H.; Li, J.; Li, Y. K.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magaña-Mendoza, L.; Mani, S.; Mao, H. S.; Markeloff, R.; Markosky, L.; Marshall, T.; Martin, M. I.; May, B.; Mayorov, A. A.; McCarthy, R.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; de Mello Neto, J. R.; Merritt, K. W.; Miettinen, H.; Mincer, A.; de Miranda, J. M.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Mudan, M.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Neis, E.; Nemethy, P.; NešiĆ, D.; Nicola, M.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Pang, M.; Para, A.; Park, C. H.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Perkins, J.; Peryshkin, A.; Peters, M.; Piekarz, H.; Pischalnikov, Y.; Podstavkov, V. M.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Pušeljić, D.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rao, M. V.; Rapidis, P. A.; Rasmussen, L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roe, N. A.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, A.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sood, P. M.; Sosebee, M.; Sotnikova, N.; Souza, M.; Spadafora, A. L.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stoianova, D. A.; Stoker, D.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Taylor, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Virador, P. R.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Wilcox, J.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhu, Q.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.
1996-10-01
A measurement of the mass of the W boson is presented based on a sample of 5982 W-->eν decays observed in pp¯ collisions at s = 1.8 TeV with the D0 detector during the 1992-1993 run. From a fit to the transverse mass spectrum, combined with measurements of the Z boson mass, the W boson mass is measured to be MW = 80.350+/-0.140\\(stat\\)+/-0.165\\(syst\\)+/-0.160\\(scale\\) GeV/c2.
Leptogenesis and neutral gauge bosons
NASA Astrophysics Data System (ADS)
Heeck, Julian; Teresi, Daniele
2016-11-01
We consider low-scale leptogenesis via right-handed neutrinos N coupled to a Z' boson, with gauged U (1 )B -L as a simple realization. Keeping the neutrinos sufficiently out of equilibrium puts strong bounds on the Z' coupling strength and mass, our focus being on light Z' and N , testable in the near future by SHiP, HPS, Belle II, and at the LHC. We show that leptogenesis could be robustly falsified in a large region of parameter space by the double observation of Z' and N , e.g. in the channel p p →Z'→N N with displaced N -decay vertex, and by several experiments searching for light Z', according to the mass of N .
Draper, Patrick; Liu Tao; Wagner, Carlos E. M.; Wang, Lian-Tao; Zhang Hao
2011-03-25
We study a limit of the nearly Peccei-Quinn-symmetric next-to-minimal supersymmetric standard model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally coexist three light singletlike particles: a scalar, a pseudoscalar, and a singlinolike DM candidate, all with masses of order 0.1-10 GeV. The decay of a standard model-like Higgs boson to pairs of the light scalars or pseudoscalars is generically suppressed, avoiding constraints from collider searches for these channels. For a certain parameter window annihilation into the light pseudoscalar and exchange of the light scalar with nucleons allow the singlino to achieve the correct relic density and a large direct-detection cross section consistent with the DM direct-detection experiments, CoGeNT and DAMA/LIBRA, preferred region simultaneously. This parameter space is consistent with experimental constraints from LEP, the Tevatron, {Upsilon}, and flavor physics.
Twisted vertex algebras, bicharacter construction and boson-fermion correspondences
NASA Astrophysics Data System (ADS)
Anguelova, Iana I.
2013-12-01
The boson-fermion correspondences are an important phenomena on the intersection of several areas in mathematical physics: representation theory, vertex algebras and conformal field theory, integrable systems, number theory, cohomology. Two such correspondences are well known: the types A and B (and their super extensions). As a main result of this paper we present a new boson-fermion correspondence of type D-A. Further, we define a new concept of twisted vertex algebra of order N, which generalizes super vertex algebra. We develop the bicharacter construction which we use for constructing classes of examples of twisted vertex algebras, as well as for deriving formulas for the operator product expansions, analytic continuations, and normal ordered products. By using the underlying Hopf algebra structure we prove general bicharacter formulas for the vacuum expectation values for two important groups of examples. We show that the correspondences of types B, C, and D-A are isomorphisms of twisted vertex algebras.
Does the supersymmetric integrability imply the integrability of Bosonic sector
Popowicz, Ziemowit
2010-03-08
The answer is no. This is demonstrated for two equations that belong to the supersymmetric Manin-Radul N = 1 Kadomtsev-Petviashvili (MRSKP) hierarchy. The first one is the N = 1 supersymmetric Sawada-Kotera equation recently considered by Tian and Liu. We define the bi-Hamiltonian structure for this equation which however does not reduce in the bosonic limit to the known bi-Hamiltonian structure. The second equation is obtained from the Lax operator of the fifth order in the supersymmetric derivatives which in the bosonic sector reduces to the system of interacted two KdV equations discovered by Drinfeld and Sokolov in 1981 and later rediscovered by Sakovich and Foursov.
The boson fermion resonance model in one dimension
NASA Astrophysics Data System (ADS)
Citro, R.; Orignac, E.
2006-05-01
We discuss the phase transitions of fermions in one dimension with a narrow Feshbach resonance described by the boson-fermion resonance model. By means of the bosonization technique, we derive a low-energy Hamiltonian of the system and show that a strongly correlated state exists, where the order parameters of the Bose condensation and superfluidity decay with the same critical exponent. We also show that density fluctuations near the Fermi wavevector are strongly suppressed as a consequence of a spin gap and a gap against the formation of phase slips. We find a Luther-Emery point where the phase slips and the spin excitations can be described in terms of pseudofermions, providing closed form expressions of the density-density correlations and the spectral functions. The relevance of our results for experiments with ultracold atomic gases subject to one-dimensional confinement is also discussed.
Quantum phase transitions in bosonic heteronuclear pairing Hamiltonians
Hohenadler, M.; Silver, A. O.; Bhaseen, M. J.; Simons, B. D.
2010-07-15
We explore the phase diagram of two-component bosons with Feshbach resonant pairing interactions in an optical lattice. It has been shown in previous work to exhibit a rich variety of phases and phase transitions, including a paradigmatic Ising quantum phase transition within the second Mott lobe. We discuss the evolution of the phase diagram with system parameters and relate this to the predictions of Landau theory. We extend our exact diagonalization studies of the one-dimensional bosonic Hamiltonian and confirm additional Ising critical exponents for the longitudinal and transverse magnetic susceptibilities within the second Mott lobe. The numerical results for the ground-state energy and transverse magnetization are in good agreement with exact solutions of the Ising model in the thermodynamic limit. We also provide details of the low-energy spectrum, as well as density fluctuations and superfluid fractions in the grand canonical ensemble.
Bosonic models with Fermi-liquid kinematics: realizations and properties
NASA Astrophysics Data System (ADS)
Goldbart, Paul; Gopalakrishnan, Sarang; Lamacraft, Austen
2011-03-01
We consider models of interacting bosons in which the single-particle kinetic energy achieves its minimum on a surface in momentum space. The kinematics of such models resembles that resulting from Pauli blocking in Fermi liquids; therefore, Shankar's renormalization-group treatment of Fermi liquids can be adapted to investigate phase transitions in these bosonic systems. We explore possible experimental realizations of such models in cold atomic gases: e.g., via spin-orbit coupling, multimode-cavity-mediated interactions, and Cooper pairing of Fermi gases in spin-dependent lattices. We address the phase structure and critical behavior of the resulting models within the framework of Ref., focusing in particular on Bose-Einstein condensation and on quantum versions of the Brazovskii transition from a superfluid to a supersolid.
Twisted vertex algebras, bicharacter construction and boson-fermion correspondences
Anguelova, Iana I.
2013-12-15
The boson-fermion correspondences are an important phenomena on the intersection of several areas in mathematical physics: representation theory, vertex algebras and conformal field theory, integrable systems, number theory, cohomology. Two such correspondences are well known: the types A and B (and their super extensions). As a main result of this paper we present a new boson-fermion correspondence of type D-A. Further, we define a new concept of twisted vertex algebra of order N, which generalizes super vertex algebra. We develop the bicharacter construction which we use for constructing classes of examples of twisted vertex algebras, as well as for deriving formulas for the operator product expansions, analytic continuations, and normal ordered products. By using the underlying Hopf algebra structure we prove general bicharacter formulas for the vacuum expectation values for two important groups of examples. We show that the correspondences of types B, C, and D-A are isomorphisms of twisted vertex algebras.
Accioly, Antonio; Dias, Marco
2004-11-15
The problem of computing the effective nonrelativistic potential U{sub D} for the interaction of charged-scalar bosons, within the context of D-dimensional electromagnetism with a cutoff, is reduced to quadratures. It is shown that U{sub 3} cannot bind a pair of identical charged-scalar bosons; nevertheless, numerical calculations indicate that boson-boson bound states do exist in the framework of three-dimensional higher-derivative electromagnetism augmented by a topological Chern-Simons term.
Carena, Marcela; Haber, Howard E.; Low, Ian; ...
2015-02-03
Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP-even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. In addition, the combinationmore » of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP-even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ.« less
Heavy Higgs bosons and the 2 TeV $W'$ boson
Dobrescu, Bogdan A.; Liu, Zhen
2015-10-19
The hints from the LHC for the existence of a W' boson of mass around 1.9 TeV point towards a certain SU(2) L × SU(2) R × U(1) B-L gauge theory with an extended Higgs sector. We show that the decays of the W' boson into heavy Higgs bosons have sizable branching fractions. Interpreting the ATLAS excess events in the search for same-sign lepton pairs plus b jets as arising from W' cascade decays, we then estimate that the masses of the heavy Higgs bosons are in the 400-700 GeV range.
Carena, Marcela; Haber, Howard E.; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E. M.
2015-02-03
Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP-even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. In addition, the combination of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP-even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ.
Carena, Marcela; Haber, Howard E.; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E.M.
2015-02-03
Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP -even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. The combination of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP -even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ
Heavy Higgs bosons and the 2 TeV $W'$ boson
Dobrescu, Bogdan A.; Liu, Zhen
2015-10-19
The hints from the LHC for the existence of a W' boson of mass around 1.9 TeV point towards a certain SU(2)_{ L} × SU(2) R × U(1) _{B-L} gauge theory with an extended Higgs sector. We show that the decays of the W' boson into heavy Higgs bosons have sizable branching fractions. Interpreting the ATLAS excess events in the search for same-sign lepton pairs plus b jets as arising from W' cascade decays, we then estimate that the masses of the heavy Higgs bosons are in the 400-700 GeV range.
General form of the boson-fermion interaction in the interacting boson-fermion model-2
NASA Astrophysics Data System (ADS)
Matus, F. A.; Barea, J.
2017-03-01
The boson-fermion interaction in the interacting boson-fermion model-2 (IBFM-2) is derived in a systematic and general form from a quadrupole-quadrupole force using several nondegenerate levels. The boson-fermion quadrupole operator employed is obtained from the boson-fermion image of the one nucleon transfer operator which in turn can be calculated following two alternative schemes: the Otsuka-Arima-Iachello and generalized Holstein-Primakoff schemes. Four different terms (two quadrupole and two exchange) were obtained. Application of the new expressions to a single-j model is studied and analyzed.
Flux-fusion anomaly test and bosonic topological crystalline insulators
Hermele, Michael; Chen, Xie
2016-10-13
Here, we introduce a method, dubbed the flux-fusion anomaly test, to detect certain anomalous symmetry fractionalization patterns in two-dimensional symmetry-enriched topological (SET) phases. We focus on bosonic systems with Z2 topological order and a symmetry group of the form G=U(1)xG', where G' is an arbitrary group that may include spatial symmetries and/or time reversal. The anomalous fractionalization patterns we identify cannot occur in strictly d=2 systems but can occur at surfaces of d=3 symmetry-protected topological (SPT) phases. This observation leads to examples of d=3 bosonic topological crystalline insulators (TCIs) that, to our knowledge, have not previously been identified. In somemore » cases, these d=3 bosonic TCIs can have an anomalous superfluid at the surface, which is characterized by nontrivial projective transformations of the superfluid vortices under symmetry. The basic idea of our anomaly test is to introduce fluxes of the U(1) symmetry and to show that some fractionalization patterns cannot be extended to a consistent action of G' symmetry on the fluxes. For some anomalies, this can be described in terms of dimensional reduction to d=1 SPT phases. We apply our method to several different symmetry groups with nontrivial anomalies, including G=U(1)×ZT2 and G=U(1)×ZP2, where ZT2 and ZP2 are time-reversal and d=2 reflection symmetry, respectively.« less
Flux-Fusion Anomaly Test and Bosonic Topological Crystalline Insulators
NASA Astrophysics Data System (ADS)
Hermele, Michael; Chen, Xie
2016-10-01
We introduce a method, dubbed the flux-fusion anomaly test, to detect certain anomalous symmetry fractionalization patterns in two-dimensional symmetry-enriched topological (SET) phases. We focus on bosonic systems with Z2 topological order and a symmetry group of the form G =U (1 )⋊G' , where G' is an arbitrary group that may include spatial symmetries and/or time reversal. The anomalous fractionalization patterns we identify cannot occur in strictly d =2 systems but can occur at surfaces of d =3 symmetry-protected topological (SPT) phases. This observation leads to examples of d =3 bosonic topological crystalline insulators (TCIs) that, to our knowledge, have not previously been identified. In some cases, these d =3 bosonic TCIs can have an anomalous superfluid at the surface, which is characterized by nontrivial projective transformations of the superfluid vortices under symmetry. The basic idea of our anomaly test is to introduce fluxes of the U(1) symmetry and to show that some fractionalization patterns cannot be extended to a consistent action of G' symmetry on the fluxes. For some anomalies, this can be described in terms of dimensional reduction to d =1 SPT phases. We apply our method to several different symmetry groups with nontrivial anomalies, including G =U (1 )×Z2T and G =U (1 )×Z2P , where Z2T and Z2P are time-reversal and d =2 reflection symmetry, respectively.
Superconductivity in the boson-fermion model with short range fermion repulsion
NASA Astrophysics Data System (ADS)
Kostyrko, Tomasz
1998-03-01
We consider influence of an on-site Coulomb repulsion U between fermions on superconducting properties of a two-component system of the wide band electrons hybridized with heavy boson-like local electron pairs^1,2. Within an RPA treatment valid for U< fermion bandwidth, we show that U almost completely suppresses superconductivity as long as a boson level stays above a Fermi level (BCS limit), reducing both Tc and a range of stability of an s-wave superconducting phase at T=0 K. In a Bose region, where the chemical potential remains pinned to the boson level, superconductivity is always stable at T=0 K and suppression of Tc is relatively small, especially for finite values of a boson mass. Above results are verified with the conclusions based on an effective t-J like hamiltonian derived by means of a canonical perturbation method from the boson-fermion model in a strong U limit. We show that the on-site boson-fermion hybridization is reduced by a factor of 2t/U (t - fermion hopping) and transforms into an intersite coupling supporting an extended s-wave superconducting order in this limit. [1em] 1. J. Ranninger and Robaszkiewicz, Physica B 135, 468 (1985). 2. R. Friedberg and T.D. Lee, Phys. Rev. B 40, 423 (1989).
Phase transitions in the boson-fermion resonance model in one dimension
NASA Astrophysics Data System (ADS)
Orignac, E.; Citro, R.
2006-06-01
We study one-dimensional fermions with photoassociation or with a narrow Fano-Feshbach resonance described by the boson-fermion resonance model. Using the bosonization technique, we derive a low-energy Hamiltonian of the system. We show that at low energy, the order parameters for the Bose condensation and fermion superfluidity become identical, while a spin gap and a gap against the formation of phase slips are formed. As a result of these gaps, charge density wave correlations decay exponentially in contrast with the phases where only bosons or only fermions are present. We find a Luther-Emery point where the phase slips and the spin excitations can be described in terms of pseudofermions. This allows us to provide closed form expressions of the density-density correlations and the spectral functions. The spectral functions of the fermions are gapped, whereas the spectral functions of the bosons remain gapless. The application of a magnetic field results in a loss of coherence between the bosons and the fermion and the disappearance of the gap. Changing the detuning has no effect on the gap until either the fermion or the boson density is reduced to zero. Finally, we discuss the formation of a Mott insulating state in a periodic potential. The relevance of our results for experiments with ultracold atomic gases subject to one-dimensional confinement is also discussed.
Connections between fermions and bosons that rotate in two dimensional harmonic traps
NASA Astrophysics Data System (ADS)
Yan, Bin; Wooten, Rachel; Greene, Chris
2016-05-01
The quantum Hall effect (QHE) was originally observed in two-dimensional electron materials in strong perpendicular magnetic fields. Theoretical treatments suggest that the QHE should also be observable in an analogous two-dimensional bosonic gas. In recent years, there has been significant interest in studying the QHE and its bosonic analog in highly-controlled atomic systems. While fermions and bosons have fundamentally different behavior, there is a connection between bosons and fermions in the presence of strong interactions. In the lowest Landau level (the strong magnetic field limit), the Hilbert subspace of N fermions with a specific total relative angular momentum, M, is isomorphic to the Hilbert subspace of N bosons with a different M. However, even though these Hilbert subspaces are isomorphic, in the presence of Coulomb repulsion their energy spectra exhibit intriguing similarities. This study solves the boson and fermion problems in their corresponding Hilbert spaces, and compares their energy level statistics, as well as the connection between their ground state wave functions.
Localization of disordered bosons and magnets in random fields
Yu, Xiaoquan; Müller, Markus
2013-10-15
We study localization properties of disordered bosons and spins in random fields at zero temperature. We focus on two representatives of different symmetry classes, hard-core bosons (XY magnets) and Ising magnets in random transverse fields, and contrast their physical properties. We describe localization properties using a locator expansion on general lattices. For 1d Ising chains, we find non-analytic behavior of the localization length as a function of energy at ω=0, ξ{sup −1}(ω)=ξ{sup −1}(0)+A|ω|{sup α}, with α vanishing at criticality. This contrasts with the much smoother behavior predicted for XY magnets. We use these results to approach the ordering transition on Bethe lattices of large connectivity K, which mimic the limit of high dimensionality. In both models, in the paramagnetic phase with uniform disorder, the localization length is found to have a local maximum at ω=0. For the Ising model, we find activated scaling at the phase transition, in agreement with infinite randomness studies. In the Ising model long range order is found to arise due to a delocalization and condensation initiated at ω=0, without a closing mobility gap. We find that Ising systems establish order on much sparser (fractal) subgraphs than XY models. Possible implications of these results for finite-dimensional systems are discussed. -- Highlights: •Study of localization properties of disordered bosons and spins in random fields. •Comparison between XY magnets (hard-core bosons) and Ising magnets. •Analysis of the nature of the magnetic transition in strong quenched disorder. •Ising magnets: activated scaling, no closing mobility gap at the transition. •Ising order emerges on sparser (fractal) support than XY order.
Plaquette boson-fermion model of cuprates
NASA Astrophysics Data System (ADS)
Altman, Ehud; Auerbach, Assa
2002-03-01
The strongly interacting Hubbard model on the square lattice is reduced to the low energy plaquette boson fermion model (PBFM). The four bosons (an antiferromagnon triplet and a d-wave hole pair), and the fermions are defined by the lowest plaquette eigenstates. We apply the contractor renormalization method of Morningstar and Weinstein to compute the boson effective interactions. The range-3 truncation error is found to be very small, signaling short hole-pair and magnon coherence lengths. The pair-hopping and magnon interactions are comparable, which explains the rapid destruction of antiferromagnetic order with emergence of superconductivity, and validates a key assumption of the projected SO(5) theory. A vacuum crossing at larger doping marks a transition into the overdoped regime. With hole fermions occupying small Fermi pockets and Andreev coupled to hole pair bosons, the PBFM yields several testable predictions for photoemission, tunneling asymmetry, and entropy measurements.
Gauge Bosons--The Ties That Bind.
ERIC Educational Resources Information Center
Hill, Christopher T.
1982-01-01
Discusses four basic forces/interactions in nature (strong force, weak force, electromagnetic force and gravity), associated with elementary particles. Focuses on "gauge bosons" (for example, photons), thought to account for strong, weak, and electromagnetic forces. (Author/JN)
Ferromagnetic properties of charged vector boson condensate
Dolgov, Alexander D.; Lepidi, Angela; Piccinelli, Gabriella E-mail: lepidi@fe.infn.it
2010-08-01
Bose-Einstein condensation of W bosons in the early universe is studied. It is shown that, in the broken phase of the standard electroweak theory, the condensed W bosons form a ferromagnetic state with aligned spins. In this case the primeval plasma may be spontaneously magnetized inside macroscopically large domains and form magnetic fields which may be the seeds for the observed today galactic and intergalactic fields. However, in a modified theory, e.g. in a theory with stronger quartic self interactions of gauge bosons e.g. due to a smaller value of the weak mixing angle, antiferromagnetic condensation is possible. In the latter case W bosons form scalar condensate with macroscopically large electric charge density i.e. with a large average value of the bilinear product of W-vector fields but with microscopically small average value of the field itself.
Factorization of the bosonic partition function
NASA Astrophysics Data System (ADS)
Alsharafat, Ayed; Chair, Noureddine
2017-04-01
The factorization formula in the non-interacting quantum field theories that relates the fermionic partition function to the bosonic partition function considered recently by Chair (2013) [3] is obtained for the harmonic oscillator using the path integral formulation. By using the latter, the fermionic partition function turns out to be the ratio of two determinants of the same operator (∂τ + ω), whose eigenmodes being both periodic on the imaginary time intervals [ 0 , 2 β ], [ 0 , β ]. The natural generalization of the factorization formula when β →2m β is derived, such a factorization implies that the bosonic oscillator at temperature β can be seen as a non-interacting mixture of a bosonic oscillator at temperature 2m β and m-fermionic oscillators at different temperatures 2 m - k β, k = 1 , 2 , … , m. As a consequence, a general relationship between the bosonic and fermionic thermal zeta functions is deduced.
The pomeron in closed bosonic string theory
Fazio, A. R.
2010-12-22
We compute the couplings of the pomeron to the first few mass levels of closed bosonic string states in flat space. We recognize the deviation from the linearity of the Regge trajectories in a five dimensional anti De Sitter background.
Kondo effect in bosonic spin liquids.
Florens, Serge; Fritz, Lars; Vojta, Matthias
2006-01-27
In a metal, a magnetic impurity is fully screened by the conduction electrons at low temperature. In contrast, impurity moments coupled to spin-1 bulk bosons, such as triplet excitations in paramagnets, are only partially screened, even at the bulk quantum critical point. We argue that this difference is not due to the quantum statistics of the host particles but instead related to the structure of the impurity-host coupling, by demonstrating that frustrated magnets with bosonic spinon excitations can display a bosonic version of the Kondo effect. However, the Bose statistics of the bulk implies distinct behavior, such as a weak-coupling impurity quantum phase transition, and perfect screening for a range of impurity spin values. We discuss implications of our results for the compound Cs2CuCl4, as well as possible extensions to multicomponent bosonic gases.
Gauge Bosons--The Ties That Bind.
ERIC Educational Resources Information Center
Hill, Christopher T.
1982-01-01
Discusses four basic forces/interactions in nature (strong force, weak force, electromagnetic force and gravity), associated with elementary particles. Focuses on "gauge bosons" (for example, photons), thought to account for strong, weak, and electromagnetic forces. (Author/JN)
Higgs boson studies at the tevatron
Herner, Kenneth
2016-05-31
We present the combination of searches for the Standard Model Higgs boson at a center-of-mass energy of √s = 1.96 TeV , using the full Run 2 dataset collected with the CDF and D0 detectors at the Fermilab Tevatron collider. We also present combined measurements of Higgs Boson production cross sections, branching ratios, and couplings to fermions and bosons. Lastly, we present tests of different spin and parity hypotheses for a particle H of mass 125 GeV produced in association with a vector boson and decaying into a pair of b quarks, and place constraints on such hypotheses using the D0 data.
Higgs boson studies at the tevatron
Herner, Kenneth
2016-05-31
We present the combination of searches for the Standard Model Higgs boson at a center-of-mass energy of √s = 1.96 TeV , using the full Run 2 dataset collected with the CDF and D0 detectors at the Fermilab Tevatron collider. We also present combined measurements of Higgs Boson production cross sections, branching ratios, and couplings to fermions and bosons. Lastly, we present tests of different spin and parity hypotheses for a particle H of mass 125 GeV produced in association with a vector boson and decaying into a pair of b quarks, and place constraints on such hypotheses using the D0more » data.« less
Lykken, Joseph; Spiropulu, Maria
2013-12-15
Experimentalists and theorists are still celebrating the Nobel-worthy discovery of the Higgs boson that was announced in July 2012 at CERN’s Large Hadron Collider. Now they are working on the profound implications of that discovery.
A Historical Profile of the Higgs Boson
Ellis, John; Gaillard, Mary K.; Nanopoulos, Dimitri V.
2012-01-31
The Higgs boson was postulated in 1964, and phenomenological studies of its possible production and decays started in the early 1970s, followed by studies of its possible productionin e{sup +} e{sup -}, {anti p}p and pp collisions, in particular. Until recently, the most sensitive searches for the Higgs boson were at LEP between 1989 and 2000, which have been complemented bysearches at the Fermilab Tevatron. The LHC has recently entered the hunt, excluding a Higgs boson over a large range of masses and revealing a tantalizing hint in the range 119 to125 GeV, and there are good prospects that the existence or otherwise of the Higgs boson will soon be established. One of the most attractive possibilities is that the Higgs bosonis accompanied by supersymmetry, though composite options have yet to be excluded. This article reviews some of the key historical developments in Higgs physics over the past half-century.
Natesan, Senthil; Wang, Tiansheng; Lukacova, Viera; Bartus, Vladimir; Khandelwal, Akash; Balaz, Stefan
2011-01-01
For a rigorous analysis of the receptor-ligand binding, speciation of the ligands caused by ionization, tautomerism, covalent hydration, and dynamic stereoisomerism needs to be considered. Each species may bind in several orientations or conformations (modes), especially for flexible ligands and receptors. A thermodynamic description of the multi-species (MS), multi-mode (MM) binding events shows that the overall association constant is equal to the weighted sum of the sums of microscopic association constants of individual modes for each species, with the weights given by the unbound fractions of individual species. This expression is a prerequisite for a precise quantitative characterization of the ligand-receptor interactions in both structure-based and ligand-based structure-activity analyses. We have implemented the MS-MM correlation expression into the Comparative Molecular Field Analysis (CoMFA), which deduces a map of the binding site from structures and binding affinities of a ligand set, in the absence of experimental structural information on the receptor. The MS-MM CoMFA approach was applied to published data for binding to transthyretin of 28 thyroxine analogs, each forming up to four ionization species under physiological conditions. The published X-ray structures of several analogs, exhibiting multiple binding modes, served as templates for the MS-MM superposition of thyroxine analogs. Additional modes were generated for compounds with flexible alkyl substituents, to identify bound conformations. The results demonstrate that the MS-MM modification improved predictive abilities of the CoMFA models, even for the standard procedure with MS-MM selected species and modes. The predicted prevalences of individual modes and the generated receptor site model are in reasonable agreement with the available X-ray data. The calibrated model can help in the design of inhibitors of transthyretin amyloid fibril formation. PMID:21476521
Conformal gravity and the bosonic string
NASA Astrophysics Data System (ADS)
Julve, J.; Tiemblo, A.; Tresguerres, R.
1987-06-01
We show that the Callan et al. effective equations of motion for the bosonic closed string in a non-trivial background may not be derived only from the bosonic part of the N=1 supergravity action of Manton and Chapline, but also from just a general conformally invariant theory of gravity. In our scheme the invariance under gauge transformations of the antisymmetric tensor field turns out to be a consequence of the metricity condition.
Di-boson production at the Tevatron
De Lentdecker, Gilles; /Rochester U.
2005-05-01
The authors present some precision measurements on electroweak physics performed at the Tevatron collider at Fermilab. Namely they report on the boson-pair production cross sections and on triple gauge boson couplings using proton anti-proton collisions collected by the CDF and D0 experiments at the center-of-mass energy of 1.96 TeV. The data correspond to an integrated luminosity of up to 324 pb{sup -1}.
SU(N) irreducible Schwinger bosons
Mathur, Manu; Raychowdhury, Indrakshi; Anishetty, Ramesh
2010-09-15
We construct SU(N) irreducible Schwinger bosons satisfying certain U(N-1) constraints which implement the symmetries of SU(N) Young tableaues. As a result all SU(N) irreducible representations are simple monomials of (N-1) types of SU(N) irreducible Schwinger bosons. Further, we show that these representations are free of multiplicity problems. Thus, all SU(N) representations are made as simple as SU(2).
Structure functions of electroweak boson and leptons
Slominski, W; Szwed, J. |
1996-04-02
The QCD structure of the electroweak bosons is reviewed and the lepton structure function is defined and calculated. The leading order splitting functions of electron into quarks are extracted, showing an important contribution from {gamma}-Z interference. Leading logarithmic QCD evolution equations are constructed and solved in the asymptotic region where log{sup 2} behavior of the Parton densities is observed. Possible applications with clear manifestation of ``resolved`` photon and weak bosons are discussed. 8 refs., 3 figs.
The Higgs boson in the Standard Model
NASA Astrophysics Data System (ADS)
Djouadi, Abdelhak; Grazzini, Massimiliano
2016-10-01
The major goal of the Large Hadron Collider is to probe the electroweak symmetry breaking mechanism and the generation of the elementary particle masses. In the Standard Model this mechanism leads to the existence of a scalar Higgs boson with unique properties. We review the physics of the Standard Model Higgs boson, discuss its main search channels at hadron colliders and the corresponding theoretical predictions. We also summarize the strategies to study its basic properties.
Diffractive Higgs boson photoproduction in ultraperipheral collisions at LHC
Gay Ducati, M. B.; Silveira, G. G.
2010-10-01
A new production mechanism for the standard model Higgs boson in ultraperipheral collisions at the LHC, which allows central exclusive diffractive production by double pomeron exchange in photon-proton processes, is presented. The Higgs boson is centrally produced by gluon fusion with two large rapidity gaps emerging in the final state, being the main experimental signature for this process. As already studied for Pomeron-Pomeron and two-photon processes, the Higgs boson photoproduction is studied within this new mechanism in proton-proton (pp) and proton-nucleus (pA) collisions, where each system has a different dynamics to be taken into account. As a result, this mechanism predicts a production cross section for pp collisions of about 1.8 fb, which is similar to that obtained in Pomeron-Pomeron processes. Besides, in pPb collisions the cross sections have increased to about 0.6 pb, being comparable with the results of two-photon processes in pAu collisions. Therefore, as the rapidity gap survival probability is an open question in high-energy physics, an analysis for different values of this probability shows how competitive the mechanisms are in the LHC kinematical regime.
Frustration of dissipation in a spin-boson model
NASA Astrophysics Data System (ADS)
Ingersent, Kevin; Duru, Alper
2009-03-01
The spin-boson model (SBM), in which a quantum two-level system couples via one component of its effective spin to a dissipative bosonic bath, has many realizations. There has been much recent interest in the SBM with a sub-Ohmic bath characterized by a power-law spectral exponent 0 < s < 1, where at zero temperature a quantum critical point separates delocalized and localized phases. Numerical renormalization group calculations have called into question [1] the validity of the long-assumed mapping between the SBM and the classical Ising chain with interactions decaying with distance |i-j| as 1/|i-j|^1+s. Attention has also fallen on a variant of the SBM in which two components of the impurity spin couple to different bosonic baths. For Ohmic case (s = 1), competition between the baths has been shown to frustrate the dissipation and reduce the coupling of the impurity to the environment [2]. The present study addresses the SBM with two sub-Ohmic baths, where dissipative effects are intrinsically stronger than for s=1. Numerical renormalization group methods are used to identify a continuous quantum phase transition in this model and to evaluate critical exponents characterizing the quantum-critical behavior in the vicinity of the transition. [1] M. Vojta et al., Phys. Rev. Lett. 94, 070604 (2005). [2] E. Novais et al., Phys. Rev. B 72, 014417 (2005). Supported by NSF Grant DMR-0710540.
Gutzwiller wave function for a model of strongly interacting bosons
Krauth, W. ); Caffarel, M. Laboratoire Dynamique des Interactions Moleculaires, Universite Paris VI, F-75252 Paris CEDEX 05 ); Bouchaud, J. )
1992-02-01
We study a model of strongly interacting lattice bosons with a Gutzwiller-type wave function that contains only on-site correlations. The variational energy and the condensate fraction associated with the variational wave function are exactly evaluated for both finite and infinite systems and compared with exact quantum Monte Carlo results in two dimensions. This ansatz for the wave function gives the correct qualitative picture of the phase diagram of this system; at commensurate densities, this system enters a Mott-insulator phase for large values of the interaction.
Neutral Supersymmetric Higgs Boson Searches
Robinson, Stephen Luke
2008-07-01
In some Supersymmetric extensions of the Standard Model, including the Minimal Supersymmetric Standard Model (MSSM), the coupling of Higgs bosons to b-quarks is enhanced. This enhancement makes the associated production of the Higgs with b-quarks an interesting search channel for the Higgs and Supersymmetry at D0. The identification of b-quarks, both online and offline, is essential to this search effort. This thesis describes the author's involvement in the development of both types of b-tagging and in the application of these techniques to the MSSM Higgs search. Work was carried out on the Level-3 trigger b-tagging algorithms. The impact parameter (IP) b-tagger was retuned and the effects of increased instantaneous luminosity on the tagger were studied. An extension of the IP-tagger to use the z-tracking information was developed. A new b-tagger using secondary vertices was developed and commissioned. A tool was developed to allow the use of large multi-run samples for trigger studies involving b-quarks. Offline, a neural network (NN) b-tagger was trained combining the existing offline lifetime based b-tagging tools. The efficiency and fake rate of the NN b-tagger were measured in data and MC. This b-tagger was internally reviewed and certified by the Collaboration and now provides the official b-tagging for all analyses using the Run IIa dataset at D0. A search was performed for neutral MSSM Higgs bosons decaying to a b{bar b} pair and produced in association with one or more b-quarks. Limits are set on the cross-section times the branching ratio for such a process. The limits were interpreted in various MSSM scenarios. This analysis uses the NN b-tagger and was the first to use this tool. The analysis also relies on triggers using the Level-3 IP b-tagging tool described previously. A likelihood discriminant was used to improve the analysis and a neural network was developed to cross-check this technique. The result of the analysis has been submitted to PRL and
Search for the Standard Model Higgs Boson in associated production with w boson at the Tevatron
Chun, Xu
2009-11-01
A search for the Standard Model Higgs boson in proton-antiproton collisions with center-of-mass energy 1.96 TeV at the Tevatron is presented in this dissertation. The process of interest is the associated production of W boson and Higgs boson, with the W boson decaying leptonically and the Higgs boson decaying into a pair of bottom quarks. The dataset in the analysis is accumulated by the D0 detector from April 2002 to April 2008 and corresponding to an integrated luminosity of 2.7 fb^{-1}. The events are reconstructed and selected following the criteria of an isolated lepton, missing transverse energy and two jets. The D0 Neural Network b-jet identification algorithm is further used to discriminate b jets from light jets. A multivariate analysis combining Matrix Element and Neural Network methods is explored to improve the Higgs boson signal significance. No evidence of the Higgs boson is observed in this analysis. In consequence, an observed (expected) limit on the ratio of σ (p$\\bar{p}$ → WH) x Br (H → b$\\bar{b}$) to the Standard Model prediction is set to be 6.7 (6.4) at 95% C.L. for the Higgs boson with a mass of 115 GeV.
Hidden sector dark matters and elusive Higgs boson(s) at the LHC
Ko, P.
2012-07-27
We consider two types of hidden sector dark matters (DM's), with and without QCD-like new strong interaction with confinement properties, and their interplays with the Standard Model (SM) Higgs boson. Assuming the hidden sector has only fermions (and gauge bosons in case of strongly interacting hidden sector), we have to introduce a real singlet scalar boson S as a messenger between the SM and the hidden sector dark matters. This singlet scalar will mix with the SM Higgs boson h, and we expect there are two Higgs-like scalar bosons H{sub 1} and H{sub 2}. Imposing all the relevant constraints from collider search bounds on Higgs boson, DM scattering cross section on proton and thermal relic density, we find that one of the two Higgs-like scalar bosons can easily escape the detections at the LHC. Recent results on the Higgs-like new boson with mass around with 125 GeV from the LHC will constrain this class of models, which is left for future study.
Boson expansions based on the random phase approximation representation
Pedrocchi, V.G.; Tamura, T.
1984-04-01
A new boson expansion theory based on the random phase approximation is presented. The boson expansions are derived here directly in the random phase approximation representation with the help of a technique that combines the use of the Usui operator with that of a new bosonization procedure, called the term-by-term bosonization method. The present boson expansion theory is constructed by retaining a single collective quadrupole random phase approximation component, a truncation that allows for a perturbative treatment of the whole problem. Both Hermitian, as well as non-Hermitian boson expansions, valid for even nuclei, are obtained.
Double Higgs-boson bremsstrahlung from W and Z bosons at supercolliders
NASA Astrophysics Data System (ADS)
Barger, V.; Han, T.; Phillips, R. J. N.
1988-11-01
We calculate the production of two standard-model neutral Higgs bosons via bremsstrahlung from a single W or Z boson in pp or e+e- collisions at supercollider energies. Observation of these processes would test the predicted HHH, HVV, and HHVV couplings (V=W or Z). For e+e--->ZHH we extend previous cross-section calculations to a more comprehensive range of energies and Higgs-boson masses, that may be accessible to future machines; we also give final-particle distributions. In the pp case we present the first calculations of the processes pp-->HHVX the cross sections are comparable to other double Higgs-boson production processes for a range of energies and masses. The presence of W or Z accompanying the Higgs-boson pair has distinct practical advantages for triggering and for separating the final state from backgrounds.
Double Higgs-boson bremsstrahlung from W and Z bosons at supercolliders
Barger, V.; Han, T.; Phillips, R.J.N.
1988-11-01
We calculate the production of two standard-model neutral Higgs bosons via bremsstrahlung from a single W or Z boson in pp or e/sup +/e/sup -/ collisions at supercollider energies. Observation of these processes would test the predicted HHH, HVV, and HHVV couplings (V = W or Z). For e/sup +/e/sup -/..-->..ZHH we extend previous cross-section calculations to a more comprehensive range of energies and Higgs-boson masses, that may be accessible to future machines; we also give final-particle distributions. In the pp case we present the first calculations of the processes pp..-->..HHVX; the cross sections are comparable to other double Higgs-boson production processes for a range of energies and masses. The presence of W or Z accompanying the Higgs-boson pair has distinct practical advantages for triggering and for separating the final state from backgrounds.
A van der Waals Equation of State for a Dilute Boson Gas
ERIC Educational Resources Information Center
Deeney, F. A.; O'Leary, J. P.
2012-01-01
An equation of state of a system is a relationship that connects the thermodynamic variables of the system such as pressure and temperature. Such equations are well known for classical gases but less so for quantum systems. In this paper we develop a van der Waals equation of state for a dilute boson gas that may be used to explain the occurrence…
A van der Waals Equation of State for a Dilute Boson Gas
ERIC Educational Resources Information Center
Deeney, F. A.; O'Leary, J. P.
2012-01-01
An equation of state of a system is a relationship that connects the thermodynamic variables of the system such as pressure and temperature. Such equations are well known for classical gases but less so for quantum systems. In this paper we develop a van der Waals equation of state for a dilute boson gas that may be used to explain the occurrence…
Competing bosonic condensates in optical lattice with a mixture of single and pair hoppings
NASA Astrophysics Data System (ADS)
Travin, V. M.; Kopeć, T. K.
2017-01-01
A system of ultra-cold atoms with single boson and pair tunneling of bosonic atoms is considered in an optical lattice at arbitrary temperature. A mean-field theory was applied to the extended Bose-Hubbard Hamiltonian describing the system in order to investigate the competition between superfluid and pair superfluid as a function of the chemical potential and the temperature. To this end we have applied a method based on the Laplace transform method for the efficient calculation of the statistical sum for the quantum Hamiltonian. These results may be of interest for experiments on cold atom systems in optical lattices.
U boson at the BES III detector
Zhu Shouhua
2007-06-01
The O(MeV) spin-1 U boson has been proposed to mediate the interaction among electron-positron and O(MeV) dark matter, in order to account for the 511 keV {gamma}-ray observation by SPI/INTEGRAL. In this paper the observability of such a kind of U boson at BESIII is investigated through the processes e{sup +}e{sup -}{yields}U{gamma} and e{sup +}e{sup -}{yields}J/{psi}{yields}e{sup +}e{sup -}U. We find that BESIII and high luminosity B factories have a comparable capacity to detect such a U boson. If the U boson decays mainly into dark matter, i.e. invisibly, BESIII can measure the coupling between the U boson and an electron-positron pair g{sub eR} (see text) down to O(10{sup -5}), and cover large parameter space which can account for 511 keV {gamma}-ray observation. On the other hand, provided that U decays mainly into the electron-positron, BESIII can detect g{sub eR} down to O(10{sup -3}), and it is hard to explore the 511 keV {gamma}-ray measurement allowed parameter space due to the irreducible QED backgrounds.
Light exotic Higgs bosons at the LHC
NASA Astrophysics Data System (ADS)
Munir, Shoaib
2017-07-01
Most models of new physics contain extended Higgs sectors with multiple Higgs bosons. The observation of an additional Higgs boson, besides the ∼ 125 GeV ‘hobs ’, will thus serve as an irrefutable evidence of physics beyond the Standard Model (SM). However, even when fairly light, these additional Higgs bosons may still have escaped detection at the Large Electron-Positron (LEP) collider, the Tevatron and the Large Hadron Collider (LHC) hitherto, owing to their highly reduced couplings to the SM particles. Therefore, in addition to the searches based on the conventional production processes of these Higgs bosons, such as gluon or vector boson fusion, possible new search modes need to be exploited at collider experiments in order to establish their signatures. We investigate here the phenomenology of pseudoscalars, with masses ranging from {O}(1) GeV to about 150 GeV, in the Next-to-Minimal Supersymmetric SM (NMSSM) and the Type-I 2-Higgs Doublet Model (2HDM) in some such atypical search channels at the LHC Run-II.
Interaction between bosonic dark matter and stars
NASA Astrophysics Data System (ADS)
Brito, Richard; Cardoso, Vitor; Macedo, Caio F. B.; Okawa, Hirotada; Palenzuela, Carlos
2016-02-01
We provide a detailed analysis of how bosonic dark matter "condensates" interact with compact stars, extending significantly the results of a recent Letter [1]. We focus on bosonic fields with mass mB , such as axions, axion-like candidates and hidden photons. Self-gravitating bosonic fields generically form "breathing" configurations, where both the spacetime geometry and the field oscillate, and can interact and cluster at the center of stars. We construct stellar configurations formed by a perfect fluid and a bosonic condensate, and which may describe the late stages of dark matter accretion onto stars, in dark-matter-rich environments. These composite stars oscillate at a frequency which is a multiple of f =2.5 ×1014(mBc2/eV ) Hz . Using perturbative analysis and numerical relativity techniques, we show that these stars are generically stable, and we provide criteria for instability. Our results also indicate that the growth of the dark matter core is halted close to the Chandrasekhar limit. We thus dispel a myth concerning dark matter accretion by stars: dark matter accretion does not necessarily lead to the destruction of the star, nor to collapse to a black hole. Finally, we argue that stars with long-lived bosonic cores may also develop in other theories with effective mass couplings, such as (massless) scalar-tensor theories.
Boson stars in higher-derivative gravity
NASA Astrophysics Data System (ADS)
Baibhav, Vishal; Maity, Debaprasad
2017-01-01
In this paper, we have constructed boson star (BS) solutions in four-dimensional scalar-Gauss-Bonnet (sGB) theory. In order to have a nontrivial effect from the Gauss-Bonnet term, we invoked nonminimal coupling between a complex scalar field and the Gauss-Bonnet term with a coupling parameter, α . We show that the scalar field can no longer take arbitrary value at the center of the star. Furthermore, boson stars in our higher-derivative theory turn out to be slightly massive but much more compact than those in the usual Einstein's gravity. Interestingly, we found that for α <-0.4 and α >0.8 , binding energy for all possible boson stars is always negative. This implies that these stars are intrinsically stable against the decay by dispersion. However, for -0.4 <α <0.8 , boson stars can have both positive and negative binding energy depending on scalar field value at the center of the star. We also present the mass-radius and mass-frequency curves for boson stars and compare them with other compact objects in gravity models derived from the Gauss-Bonnet term.
NASA Astrophysics Data System (ADS)
Cao, Zheng; Cárdenas-Avendaño, Alejandro; Zhou, Menglei; Bambi, Cosimo; Herdeiro, Carlos A. R.; Radu, Eugen
2016-10-01
The present paper is a sequel to our previous work [1] in which we studied the iron Kα line expected in the reflection spectrum of Kerr black holes with scalar hair. These metrics are solutions of Einstein's gravity minimally coupled to a massive, complex scalar field. They form a continuous bridge between a subset of Kerr black holes and a family of rotating boson stars depending on one extra parameter, the dimensionless scalar hair parameter q, ranging from 0 (Kerr black holes) to 1 (boson stars). Here we study the limiting case q = 1, corresponding to rotating boson stars. For comparison, spherical boson stars are also considered. We simulate observations with XIS/Suzaku. Using the fact that current observations are well fit by the Kerr solution and thus requiring that acceptable alternative compact objects must be compatible with a Kerr fit, we find that some boson star solutions are relatively easy to rule out as potential candidates to explain astrophysical black holes, while other solutions, which are neither too dilute nor too compact are more elusive and we argue that they cannot be distinguished from Kerr black holes by the analysis of the iron line with current X-ray facilities.
Ratio method of measuring W boson mass
Guo, Feng
2010-08-01
This dissertation describes an alternative method of measuring the W boson mass in DØ experiment. Instead of extracting M_{W} from the fitting of W → ev fast Monte Carlo simulations to W → ev data as in the standard method, we make the direct fit of transverse mass between W → ev data and Z → ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (M_{W}/M_{Z}). Given the precisely measured Z boson mass, W mass is directly fitted from W → ev and Z → ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb^{-1} DØ Run IIa dataset, ratio method gives M_{W} = 80435 ± 43(stat) ± 26(sys) MeV.
Nonequilibrium dynamics of spin-boson models from phase-space methods
NASA Astrophysics Data System (ADS)
Piñeiro Orioli, Asier; Safavi-Naini, Arghavan; Wall, Michael L.; Rey, Ana Maria
2017-09-01
An accurate description of the nonequilibrium dynamics of systems with coupled spin and bosonic degrees of freedom remains theoretically challenging, especially for large system sizes and in higher than one dimension. Phase-space methods such as the truncated Wigner approximation (TWA) have the advantage of being easily scalable and applicable to arbitrary dimensions. In this work we adapt the TWA to generic spin-boson models by making use of recently developed algorithms for discrete phase spaces [J. Schachenmayer, A. Pikovski, and A. M. Rey, Phys. Rev. X 5, 011022 (2015), 10.1103/PhysRevX.5.011022]. Furthermore we go beyond the standard TWA approximation by applying a scheme based on the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy of equations to our coupled spin-boson model. This allows us, in principle, to study how systematically adding higher-order corrections improves the convergence of the method. To test various levels of approximation we study an exactly solvable spin-boson model, which is particularly relevant for trapped-ion arrays. Using TWA and its BBGKY extension we accurately reproduce the time evolution of a number of one- and two-point correlation functions in several dimensions and for an arbitrary number of bosonic modes.
Ground-state properties of few dipolar bosons in a quasi-one-dimensional harmonic trap
Deuretzbacher, F.; Cremon, J. C.; Reimann, S. M.
2010-06-15
We study the ground state of few bosons with repulsive dipole-dipole interaction in a quasi-one-dimensional harmonic trap by means of the exact diagonalization method. Up to three interaction regimes are found, depending on the strength of the dipolar interaction and the ratio of transverse to axial oscillator lengths: a regime where the dipolar Bose gas resembles a system of weakly {delta}-interacting bosons, a second regime where the bosons are fermionized, and a third regime where the bosons form a Wigner crystal. In the first two regimes, the dipole-dipole potential can be replaced by a {delta} potential. In the crystalline state, the overlap between the localized wave packets is strongly reduced and all the properties of the boson system equal those of its fermionic counterpart. The transition from the Tonks-Girardeau gas to the solidlike state is accompanied by a rapid increase of the interaction energy and a considerable change of the momentum distribution, which we trace back to the different short-range correlations in the two interaction regimes.
Boson peak, Ioffe-Regel Crossover, and Liquid-Liquid phase transition in Supercooled Water
NASA Astrophysics Data System (ADS)
Kumar, Pradeep
We have investigated the onset of Boson peak in a model of liquid water which exhibits a clear first-order phase transition between a low-density liquid phase and a high-density liquid phase of water at low temperature and high pressure. We find that the at low pressures, the onset of Boson peak coincides with the Widom-line of the system. At high pressures, the onset occurs at the transition temperature between the two liquids. Furthermore, we show that at both low and high pressure, the frequency of the Boson peak coincides with the Ioffe-Regel crossover of the transverse phonons, suggesting that the breakdown of Debye behavior is a general feature of Ioffe-Regel limit crossover in supercooled water. The frequency of the Boson peak is weakly pressure dependent and decreases with increasing pressure. Our work bridges gap between the experimental results on the Boson peak nanoconfined water and the behavior that one would expect from a bulk system.
New Microscopic foundation of Interacting Boson Model and collectivities in exotic nuclei
Nomura, K.; Shimizu, N.; Otsuka, T.
2009-01-28
We propose a novel way of determining the Hamiltonian of the Interacting Boson Model (IBM), based on the Mean-field theory. The quadrupole deformations in a fermion system, indicated by a Potential Energy Surface (PES) obtained by the constrained Skyrme Hartree-Fock calculations, are mapped, to a good approximation, onto the appropriate boson system. A merit is that levels and wave functions of excited states are calculated with the exact treatments of angular momentum and particle number. The validity of the process is examined for Sm and Ba isotopes, and predictions are made for unexplored territories on the nuclear chart, namely the right-lower corner of {sup 208}Pb.
Expansion dynamics in a one-dimensional hard-core boson model with three-body interactions
Ren, Jie; Wu, Yin-Zhong; Xu, Xue-Fen
2015-01-01
Using the adaptive time-dependent density matrix renormalization group method, we numerically investigate the expansion dynamics of bosons in a one-dimensional hard-core boson model with three-body interactions. It is found that the bosons expand ballistically with weak interaction, which are obtained by local density and the radius Rn. It is shown that the expansion velocity V, obtained from Rn = Vt, is dependent on the number of bosons. As a prominent result, the expansion velocity decreases with the enhancement of three-body interaction. We further study the dynamics of the system, which quenches from the ground state with two-thirds filling, the results indicate the expansion is also ballistic in the gapless phase regime. It could help us detect the phase transition in the system. PMID:26435319
Fingerprints of a Bosonic Symmetry-Protected Topological State in a Quantum Point Contact
NASA Astrophysics Data System (ADS)
Zhang, Rui-Xing; Liu, Chao-Xing
2017-05-01
In this work, we study the transport through a quantum point contact for bosonic helical liquid that exists at the edge of a bilayer graphene under a strong magnetic field. We identify "smoking gun" transport signatures to distinguish a bosonic symmetry-protected topological (BSPT) state from a fermionic two-channel quantum spin Hall (QSH) state in this system. In particular, a novel charge-insulator-spin-conductor phase is found for the BSPT state, while either the charge-insulator-spin-insulator or the charge-conductor-spin-conductor phase is expected for the two-channel QSH state. Consequently, a simple transport measurement will reveal the fingerprint of bosonic topological physics in bilayer graphene systems.
GENERAL: Q-Deformed Bosons at Quasi-classical Limit of SO(3)
NASA Astrophysics Data System (ADS)
Zhang, Li; Gao, Yi-Bo; Li, Yan-Min
2009-03-01
When a boson interacts with another to form a composite system with SO(3) dynamic symmetry, it is shown that there exists the q-deformed bosonic excitation satisfying the q-deformed Heisenberg commutation relation in the quasi-classical limit that the angular momentum j for SO(3) is large, but not infinite. In second quantization this quasi-excitation is associated with the boson realization of SO(3) Lie algebra. Physically, the phenomena of q-deformed excitation can happen in many models of quantum dynamics, such as super emission from a system of many identical two-level atoms, the spin wave in Heisenberg chain, the high spin precession and the coherent output of Bose-Einstein atoms in a trap. Especially, in these models, the deformation parameter q is well defined intrinsically by a conservative quantity, such as the total atomic number and the angular momentum.
Equivalence between spin Hamiltonians and boson sampling
NASA Astrophysics Data System (ADS)
Peropadre, Borja; Aspuru-Guzik, Alán; García-Ripoll, Juan José
2017-03-01
Aaronson and Arkhipov showed that predicting or reproducing the measurement statistics of a general linear optics circuit with a single Fock-state input is a classically hard problem. Here we show that this problem, known as boson sampling, is as hard as simulating the short time evolution of a large but simple spin model with long-range X Y interactions. The conditions for this equivalence are the same for efficient boson sampling, namely, having a small number of photons (excitations) as compared to the number of modes (spins). This mapping allows efficient implementations of boson sampling in small quantum computers and simulators and sheds light on the complexity of time evolution with critical spin models.
Inevitable emergence of composite gauge bosons
NASA Astrophysics Data System (ADS)
Suzuki, Mahiko
2017-09-01
A simple theorem is proved: When a gauge-invariant local field theory is written in terms of matter fields alone, a composite gauge boson or bosons must be formed dynamically. The theorem results from the fact that the Noether current vanishes in such theories. The proof is carried out by use of the charge-field algebra at equal time in the Heisenberg picture together with the well-established analyticity of the form factor of the current. While there is no need of diagram calculation for the proof, we demonstrate in the leading 1 /N expansion of the existing models what the theorem means in diagrams and how the composite gauge boson emerges.
Approximate gauge symmetry of composite vector bosons
NASA Astrophysics Data System (ADS)
Suzuki, Mahiko
2010-08-01
It can be shown in a solvable field theory model that the couplings of the composite vector bosons made of a fermion pair approach the gauge couplings in the limit of strong binding. Although this phenomenon may appear accidental and special to the vector bosons made of a fermion pair, we extend it to the case of bosons being constituents and find that the same phenomenon occurs in a more intriguing way. The functional formalism not only facilitates computation but also provides us with a better insight into the generating mechanism of approximate gauge symmetry, in particular, how the strong binding and global current conservation conspire to generate such an approximate symmetry. Remarks are made on its possible relevance or irrelevance to electroweak and higher symmetries.
Light gauge boson in rare K decay
NASA Astrophysics Data System (ADS)
Chen, Chuan-Hung; Nomura, Takaaki
2016-12-01
We study the production of a light gauge boson in K- →π- X decay, where the associated new charge current is not conserved. It is found that the process can be generated by the tree-level W-boson annihilation and loop-induced s → dX. We find that it strongly depends on the SU (3) limit or the unique gauge coupling to the quarks, whether the decay amplitude of K- →π- X in the W-boson annihilation is suppressed by mX2 ɛX ṡpK; however, no such suppression is found via the loop-induced s → dX. The constraints on the relevant couplings are studied.
Solid state boson condensation model of cold fusion
Waber, J.T.
1994-12-31
This theoretical study is based on the second suggestion of Leaf Turner which was independently developed by Chubb and Chubb. It lead to the selection rule, Bosons In, Bosons Out, which helps to explain the low yield of tritons, protons, neutrons and 3He. The production of the boson 3He has now been correlated with simultaneous production of excess heat.
Cosmic expansion from boson and fermion fields
NASA Astrophysics Data System (ADS)
de Souza, Rudinei C.; Kremer, Gilberto M.
2011-06-01
This paper consists in analyzing an action that describes boson and fermion fields minimally coupled to the gravity and a common matter field. The self-interaction potentials of the fields are not chosen a priori but from the Noether symmetry approach. The Noether forms of the potentials allow the boson field to play the role of dark energy and matter and the fermion field to behave as standard matter. The constant of motion and the cyclic variable associated with the Noether symmetry allow the complete integration of the field equations, whose solution produces a universe with alternated periods of accelerated and decelerated expansion.
Theoretical Survey of Higgs Boson and Axions
Morales, Robert O.
2000-04-05
The success as well as the problems of the minimal Standard Model are recalled. The authors survey essentially this Model and the theory of the standard axion (Nambu-Goldstone boson). Possible invisible and visualized (theoretical) axions are discussed as are certain astrophysical aspects of the existence of an axion. They survey also axion cosmology in superstring models and its consequence, in the new anomaly cancellation mechanism to the sense of Green and Schwarz. Recent results for the search of the Higgs boson, and the axion are resumed. A great important is reserved for discussion of the Standard Model.
W and Z boson production (CDF)
Sliwa, Krzysztof; /Tufts U.
2009-01-01
Precise studies of rapidity distributions and asymmetries in W and Z boson production offer important constraints on the parton distribution functions describing the structure of protons. Improving the knowledge of the parton content of protons can help avoid systematic limitations in measuring the mass of the W boson. Measurements of Z rapidity and of charge asymmetry as a function of W rapidity in CDF Run-II datasets corresponding to the integrated luminosities of 2.1 fb{sup -1} and 1fb{sup -1}, respectively, are presented.
ASSOCIATED HIGGS BOSON PRODUCTION WITH HEAVY QUARKS.
DAWSON,S.ORR,L.H.REINA,L.WACKEROTH,D.
2003-03-15
The production of a Higgs boson in association with a pair of e quarks will play a very important role at both hadron and lepton colliders. We review the status of theoretical predictions and their relevance to Higgs boson studies, with particular emphasis on the recently calculated NLO QCD corrections to the inclusive cross section for p{bar p}, pp {yields} t{bar t}h. We conclude by briefly discussing the case of exclusive b{bar b}h production and the potential of this process in revealing signals of new physics beyond the Standard Model.
Higgs boson photoproduction at the LHC
Ducati, M. B. Gay; Silveira, G. G.
2011-07-15
We present the current development of the photoproduction approach for the Higgs boson with its application to pp and pA collisions at the LHC. We perform a different analysis for the Gap Survival Probability, where we consider a probability of 3% and also a more optimistic value of 10% based on the HERA data for dijet production. As a result, the cross section for the exclusive Higgs boson production is about 2 fb and 6 fb in pp collisions and 617 and 2056 fb for pPb collisions, considering the gap survival factor of 3% and 10%, respectively.
Bilayer Graphene as a Platform for Bosonic Symmetry-Protected Topological States
NASA Astrophysics Data System (ADS)
Bi, Zhen; Zhang, Ruixing; You, Yi-Zhuang; Young, Andrea; Balents, Leon; Liu, Chao-Xing; Xu, Cenke
2017-03-01
Bosonic symmetry protected topological (BSPT) states, the bosonic analogue of topological insulators, have attracted enormous theoretical interest in the last few years. Although BSPT states have been classified by various approaches, there is so far no successful experimental realization of any BSPT state in two or higher dimensions. In this paper, we propose that a two-dimensional BSPT state with U (1 )×U (1 ) symmetry can be realized in bilayer graphene in a magnetic field. Here the two U (1 ) symmetries represent total spin Sz and total charge conservation, respectively. The Coulomb interaction plays a central role in this proposal—it gaps out all the fermions at the boundary, so that only bosonic charge and spin degrees of freedom are gapless and protected at the edge. Based on the above conclusion, we propose that the bulk quantum phase transition between the BSPT and trivial phase, which can be driven by applying both magnetic and electric fields, can become a "bosonic phase transition" with interactions. That is, only bosonic modes close their gap at the transition, which is fundamentally different from all the well-known topological insulator to trivial insulator transitions that occur for free fermion systems. We discuss various experimental consequences of this proposal.
Rapidly rotating boson molecules with long- or short-range repulsion: An exact diagonalization study
Baksmaty, Leslie O.; Yannouleas, Constantine; Landman, Uzi
2007-02-15
The Hamiltonian for a small number N{<=}11 of bosons in a rapidly rotating harmonic trap, interacting via a short range (contact potential) or a long range (Coulomb) interaction, is studied via an exact diagonalization in the lowest Landau level. Our analysis shows that, for both low and high fractional fillings, the bosons localize and form rotating boson molecules (RBMs) consisting of concentric polygonal rings. Focusing on systems with the number of trapped atoms sufficiently large to form multiring bosonic molecules, we find that, as a function of the rotational frequency and regardless of the type of repulsive interaction, the ground-state angular momenta grow in specific steps that coincide with the number of localized bosons on each concentric ring. Comparison of the conditional probability distributions (CPDs) for both interactions suggests that the degree of crystalline correlations appears to depend more on the fractional filling {nu} than on the range of the interaction. The RBMs behave as nonrigid rotors, i.e., the concentric rings rotate independently of each other. At filling fractions {nu}<1/2, we observe well developed crystallinity in the CPDs (two-point correlation functions). For larger filling fractions {nu}>1/2, observation of similar molecular patterns requires consideration of even higher-order correlation functions.
Free compact boson on branched covering of the torus
NASA Astrophysics Data System (ADS)
Liu, Feihu
2017-08-01
We have studied the partition function of a free compact boson on a n-sheeted covering of torus gluing along m branch cuts. It is interesting because when the branched cuts are chosen to be real, the partition function is related to the n-th Rényi entanglement entropy of m disjoint intervals in a finite system at finite temperature. After proposing a canonical homology basis and its dual basis of the covering surface, we find that the partition function can be written in terms of theta functions.
Phases of dipolar bosons in a bilayer geometry
NASA Astrophysics Data System (ADS)
Cinti, Fabio; Wang, Daw-Wei; Boninsegni, Massimo
2017-02-01
We study, by first-principles computer simulations, the low-temperature phase diagram of bosonic dipolar gases in a bilayer geometry as a function of the two control parameters, i.e., the in-plane density and the interlayer distance. We observe four distinct phases, namely, paired and decoupled superfluids, as well as a crystal of dimers and one consisting of two aligned crystalline layers. A direct quantum phase transition from a dimer crystal to two independent superfluids is observed in a relatively wide range of parameters. No supersolid phase is predicted for this system.
Chiral Floquet Phases of Many-Body Localized Bosons
NASA Astrophysics Data System (ADS)
Po, Hoi Chun; Fidkowski, Lukasz; Morimoto, Takahiro; Potter, Andrew C.; Vishwanath, Ashvin
2016-10-01
We construct and classify chiral topological phases in driven (Floquet) systems of strongly interacting bosons, with finite-dimensional site Hilbert spaces, in two spatial dimensions. The construction proceeds by introducing exactly soluble models with chiral edges, which in the presence of many-body localization (MBL) in the bulk are argued to lead to stable chiral phases. These chiral phases do not require any symmetry and in fact owe their existence to the absence of energy conservation in driven systems. Surprisingly, we show that they are classified by a quantized many-body index, which is well defined for any MBL Floquet system. The value of this index, which is always the logarithm of a positive rational number, can be interpreted as the entropy per Floquet cycle pumped along the edge, formalizing the notion of quantum-information flow. We explicitly compute this index for specific models and show that the nontrivial topology leads to edge thermalization, which provides an interesting link between bulk topology and chaos at the edge. We also discuss chiral Floquet phases in interacting fermionic systems and their relation to chiral bosonic phases.
Adhikari, Sadhan K.; Salasnich, Luca
2007-05-15
We investigate the mixing-demixing transition and the collapse in a quasi-two-dimensional degenerate boson-fermion mixture (DBFM) with a bosonic vortex. We solve numerically a quantum-hydrodynamic model based on a new density functional which accurately takes into account the dimensional crossover. It is demonstrated that with the increase of interspecies repulsion, a mixed state of DBFM could turn into a demixed state. The system collapses for interspecies attraction above a critical value which depends on the vortex quantum number. For interspecies attraction just below this critical limit there is almost complete mixing of boson and fermion components. Such mixed and demixed states of a DBFM could be experimentally realized by varying an external magnetic field near a boson-fermion Feshbach resonance, which will result in a continuous variation of interspecies interaction.
Non-Markovian dynamics of fully coupled fermionic and bosonic oscillators
NASA Astrophysics Data System (ADS)
Sargsyan, V. V.; Lacroix, D.; Adamian, G. G.; Antonenko, N. V.
2017-03-01
The non-Markovian Langevin approach is applied to study the dynamics of fermionic (bosonic) oscillator linearly coupled to a fermionic (bosonic) environment. The analytical expressions for occupation numbers in two different types of couplings (rotating-wave approximation and fully coupled) are compared and discussed. The weak-coupling and high- and low-temperature limits are considered as well. The conditions under which the environment imposes its thermal equilibrium on the collective subsystem are discussed. The sameness of the results, obtained with both the Langevin approach and the discretized environment method are shown. Short- and long-time nonequilibrium dynamics of fermionic and bosonic open quantum systems are analyzed both analytically and numerically.
Resummation of high order corrections in Higgs boson plus jet production at the LHC
Sun, Peng; Isaacson, Joshua; Yuan, C. -P.; ...
2017-02-22
We study the effect of multiple parton radiation to Higgs boson plus jet production at the LHC. The large logarithms arising from the small imbalance in the transverse momentum of the Higgs boson plus jet final state system are resummed to all orders in the expansion of the strong interaction coupling at the accuracy of Next-to-Leading Logarithm (NLL), by applying the transverse momentum dependent (TMD) factorization formalism. We show that the appropriate resummation scale should be the jet transverse momentum, rather than the partonic center of mass energy which has been normally used in the TMD resummation formalism. Furthermore, themore » transverse momentum distribution of the Higgs boson, particularly near the lower cut-off applied on the jet transverse momentum, can only be reliably predicted by the resummation calculation which is free of the so-called Sudakov-shoulder singularity problem, present in fixed-order calculations.« less
Memory Effect Manifested by a Boson Peak in Metallic Glass
NASA Astrophysics Data System (ADS)
Luo, P.; Li, Y. Z.; Bai, H. Y.; Wen, P.; Wang, W. H.
2016-04-01
We explore the correlation between a boson peak and structural relaxation in a typical metallic glass. Consistent with enthalpy recovery, a boson peak shows a memory effect in an aging-and-scan procedure. Single-step isothermal aging produces a monotonic decrease of enthalpy and boson peak intensity; for double-step isothermal aging, both enthalpy and boson peak intensity experience, coincidently, an incipient increase to a maximum and a subsequent decrease toward the equilibrium state. Our results indicate a direct link between slow structural relaxation and fast boson peak dynamics, which presents a profound understanding of the two dynamic behaviors in glass.