Science.gov

Sample records for four-level single-photon quantum

  1. Single photon quantum cryptography.

    PubMed

    Beveratos, Alexios; Brouri, Rosa; Gacoin, Thierry; Villing, André; Poizat, Jean-Philippe; Grangier, Philippe

    2002-10-28

    We report the full implementation of a quantum cryptography protocol using a stream of single photon pulses generated by a stable and efficient source operating at room temperature. The single photon pulses are emitted on demand by a single nitrogen-vacancy color center in a diamond nanocrystal. The quantum bit error rate is less that 4.6% and the secure bit rate is 7700 bits/s. The overall performances of our system reaches a domain where single photons have a measurable advantage over an equivalent system based on attenuated light pulses.

  2. Quantum identity authentication with single photon

    NASA Astrophysics Data System (ADS)

    Hong, Chang ho; Heo, Jino; Jang, Jin Gak; Kwon, Daesung

    2017-10-01

    Quantum identity authentication with single photons is proposed in the paper. It can verify a user's identity without exposing to an authentication key information. The protocol guarantees high efficiency in that it can verify two bits of authentication information using just a single photon. The security of our authentication scheme is analyzed and confirmed in the case of a general attack. Moreover, the proposed protocol is practicable with current technology. Our quantum identity authentication protocol does not require quantum memory registration and any entangled photon sources.

  3. Quantum Key Distribution Using Polarized Single Photons

    DTIC Science & Technology

    2009-04-01

    Cu-O high-temperature superconducting materials, and ferromagnet /superconductor nano-bilayer structures. 15. SUBJECT TERMS Quantum communications...based on high-temperature superconducting materials and ferromagnet /superconductor NiCu/Nb nano-bilayer structures. Time- resolved photoresponse...NOTES none 20090724231 14. ABSTRACT Exhaustive research, development, and testing studies were performed on novel superconducting single-photon

  4. Quantum information-holding single-photon router based on spontaneous emission

    NASA Astrophysics Data System (ADS)

    Yan, GuoAn; Qiao, HaoXue; Lu, Hua; Chen, AiXi

    2017-09-01

    In this paper, we propose a single-photon router via the use of a four-level atom system coupled with two one-dimensional coupled-resonator waveguides. A single photon can be directed from one quantum channel into another by atomic spontaneous emission. The coherent resonance and the photonic bound states lead to the perfect reflection appearing in the incident channel. The fidelity of the atom is related to the magnitude of the coupling strength and can reach unit when the coupling strength matches g a = g b . This shows that the transfer of a single photon into another quantum channel has no influence on the fidelity at special points.

  5. Quantum teleportation with a quantum dot single photon source.

    PubMed

    Fattal, D; Diamanti, E; Inoue, K; Yamamoto, Y

    2004-01-23

    We report the experimental demonstration of a quantum teleportation protocol with a semiconductor single photon source. Two qubits, a target and an ancilla, each defined by a single photon occupying two optical modes (dual-rail qubit), were generated independently by the single photon source. Upon measurement of two modes from different qubits and postselection, the state of the two remaining modes was found to reproduce the state of the target qubit. In particular, the coherence between the target qubit modes was transferred to the output modes to a large extent. The observed fidelity is 80%, in agreement with the residual distinguishability between consecutive photons from the source. An improved version of this teleportation scheme using more ancillas is the building block of the recent Knill, Laflamme, and Milburn proposal for efficient linear optics quantum computation.

  6. Multimode quantum states with single photons carrying orbital angular momentum.

    PubMed

    Song, Xin-Bing; Fu, Shi-Yao; Zhang, Xiong; Yang, Zhen-Wei; Zeng, Qiang; Gao, Chunqing; Zhang, Xiangdong

    2017-06-15

    We propose and experimentally demonstrate a scheme for generating multimode quantum states with single photons carrying orbital angular momentum (OAM). Various quantum states have been realized by superposing multiple OAM modes of single photons in two possible paths. These quantum states exhibit NOON-like "super-resolving" interference behavior for the multiple OAM modes of single photons. Compared with the NOON states using many photons, these states are not only easily prepared, but also robust to photon losses. They may find potential applications in quantum optical communication and recognizing defects or objects. The method to identify a particular kind of defect has been demonstrated both theoretically and experimentally.

  7. Single-photon quantum router with multiple output ports

    PubMed Central

    Yan, Wei-Bin; Fan, Heng

    2014-01-01

    The routing capability is a requisite in quantum network. Although the quantum routing of signals has been investigated in various systems both in theory and experiment, the general form of quantum routing with many output terminals still needs to be explored. Here we propose a scheme to achieve the multi-channel quantum routing of the single photons in a waveguide-emitter system. The channels are composed by the waveguides and are connected by intermediate two-level emitters. By adjusting the intermediate emitters, the output channels of the input single photons can be controlled. This is demonstrated in the cases of one output channel, two output channels and the generic N output channels. The results show that the multi-channel quantum routing of single photons can be well achieved in the proposed system. This offers a scheme for the experimental realization of general quantum routing of single photons. PMID:24769619

  8. Single-photon quantum router with multiple output ports.

    PubMed

    Yan, Wei-Bin; Fan, Heng

    2014-04-28

    The routing capability is a requisite in quantum network. Although the quantum routing of signals has been investigated in various systems both in theory and experiment, the general form of quantum routing with many output terminals still needs to be explored. Here we propose a scheme to achieve the multi-channel quantum routing of the single photons in a waveguide-emitter system. The channels are composed by the waveguides and are connected by intermediate two-level emitters. By adjusting the intermediate emitters, the output channels of the input single photons can be controlled. This is demonstrated in the cases of one output channel, two output channels and the generic N output channels. The results show that the multi-channel quantum routing of single photons can be well achieved in the proposed system. This offers a scheme for the experimental realization of general quantum routing of single photons.

  9. Quantum private comparison employing single-photon interference

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Xiao, Di; Huang, Wei; Jia, Heng-Yue; Song, Ting-Ting

    2017-07-01

    As a typical quantum cryptographic task between distrustful participants, quantum private comparison (QPC) has attracted a lot of attention in recent years. Here we propose two QPC protocols employing single-photon interference, a typical and interesting technology for quantum communications. Compared with the previous QPC protocols employing normal single states or entangled states, the proposed protocols achieve lower communication complexity utilizing the characteristics of single-photon interference. And we also proved the security of the proposed protocols in theory.

  10. A Single-Photon Subtractor for Multimode Quantum States

    NASA Astrophysics Data System (ADS)

    Ra, Young-Sik; Jacquard, Clément; Averchenko, Valentin; Roslund, Jonathan; Cai, Yin; Dufour, Adrien; Fabre, Claude; Treps, Nicolas

    2016-05-01

    In the last decade, single-photon subtraction has proved to be key operations in optical quantum information processing and quantum state engineering. Implementation of the photon subtraction has been based on linear optics and single-photon detection on single-mode resources. This technique, however, becomes unsuitable with multimode resources such as spectrally multimode squeezed states or continuous variables cluster states. We implement a single-photon subtractor for such multimode resources based on sum-frequency generation and single-photon detection. An input multimode quantum state interacts with a bright control beam whose spectrum has been engineered through ultrafast pulse-shaping. The multimode quantum state resulting from the single-photon subtractor is analyzed with multimode homodyne detection whose local oscillator spectrum is independently engineered. We characterize the single-photon subtractor via coherent-state quantum process tomography, which provides its mode-selectivity and subtraction modes. The ability to simultaneously control the state engineering and its detection ensures both flexibility and scalability in the production of highly entangled non-Gaussian quantum states.

  11. Single-photon electroluminescence for on-chip quantum networks

    NASA Astrophysics Data System (ADS)

    Bentham, C.; Hallett, D.; Prtljaga, N.; Royall, B.; Vaitiekus, D.; Coles, R. J.; Clarke, E.; Fox, A. M.; Skolnick, M. S.; Itskevich, I. E.; Wilson, L. R.

    2016-10-01

    An electrically driven single-photon source has been monolithically integrated with nano-photonic circuitry. Electroluminescent emission from a single InAs/GaAs quantum dot (QD) is channelled through a suspended nanobeam waveguide. The emission line has a linewidth of below 6 μeV, demonstrating the ability to have a high coherence, electrically driven, waveguide coupled QD source. The single-photon nature of the emission is verified by g ( 2 ) ( τ ) correlation measurements. Moreover, in a cross-correlation experiment, with emission collected from the two ends of the waveguide, the emission and propagation of single photons from the same QD is confirmed. This work provides the basis for the development of electrically driven on-chip single-photon sources, which can be readily coupled to waveguide filters, directional couplers, phase shifters, and other elements of quantum photonic networks.

  12. Demonstration of quantum permutation algorithm with a single photon ququart.

    PubMed

    Wang, Feiran; Wang, Yunlong; Liu, Ruifeng; Chen, Dongxu; Zhang, Pei; Gao, Hong; Li, Fuli

    2015-06-05

    We report an experiment to demonstrate a quantum permutation determining algorithm with linear optical system. By employing photon's polarization and spatial mode, we realize the quantum ququart states and all the essential permutation transformations. The quantum permutation determining algorithm displays the speedup of quantum algorithm by determining the parity of the permutation in only one step of evaluation compared with two for classical algorithm. This experiment is accomplished in single photon level and the method exhibits universality in high-dimensional quantum computation.

  13. Interferometric Quantum-Nondemolition Single-Photon Detectors

    NASA Technical Reports Server (NTRS)

    Kok, Peter; Lee, Hwang; Dowling, Jonathan

    2007-01-01

    Two interferometric quantum-nondemolition (QND) devices have been proposed: (1) a polarization-independent device and (2) a polarization-preserving device. The prolarization-independent device works on an input state of up to two photons, whereas the polarization-preserving device works on a superposition of vacuum and single- photon states. The overall function of the device would be to probabilistically generate a unique detector output only when its input electromagnetic mode was populated by a single photon, in which case its output mode would also be populated by a single photon. Like other QND devices, the proposed devices are potentially useful for a variety of applications, including such areas of NASA interest as quantum computing, quantum communication, detection of gravity waves, as well as pedagogical demonstrations of the quantum nature of light. Many protocols in quantum computation and quantum communication require the possibility of detecting a photon without destroying it. The only prior single- photon-detecting QND device is based on quantum electrodynamics in a resonant cavity and, as such, it depends on the photon frequency. Moreover, the prior device can distinguish only between one photon and no photon. The proposed interferometric QND devices would not depend on frequency and could distinguish between (a) one photon and (b) zero or two photons. The first proposed device is depicted schematically in Figure 1. The input electromagnetic mode would be a superposition of a zero-, a one-, and a two-photon quantum state. The overall function of the device would be to probabilistically generate a unique detector output only when its input electromagnetic mode was populated by a single photon, in which case its output mode also would be populated by a single photon.

  14. Quantum interference of independently generated telecom-band single photons

    SciTech Connect

    Patel, Monika; Altepeter, Joseph B.; Huang, Yu-Ping; Oza, Neal N.; Kumar, Prem

    2014-12-04

    We report on high-visibility quantum interference of independently generated telecom O-band (1310 nm) single photons using standard single-mode fibers. The experimental data are shown to agree well with the results of simulations using a comprehensive quantum multimode theory without the need for any fitting parameter.

  15. Single photon sources with single semiconductor quantum dots

    NASA Astrophysics Data System (ADS)

    Shan, Guang-Cun; Yin, Zhang-Qi; Shek, Chan Hung; Huang, Wei

    2014-04-01

    In this contribution, we briefly recall the basic concepts of quantum optics and properties of semiconductor quantum dot (QD) which are necessary to the understanding of the physics of single-photon generation with single QDs. Firstly, we address the theory of quantum emitter-cavity system, the fluorescence and optical properties of semiconductor QDs, and the photon statistics as well as optical properties of the QDs. We then review the localization of single semiconductor QDs in quantum confined optical microcavity systems to achieve their overall optical properties and performances in terms of strong coupling regime, efficiency, directionality, and polarization control. Furthermore, we will discuss the recent progress on the fabrication of single photon sources, and various approaches for embedding single QDs into microcavities or photonic crystal nanocavities and show how to extend the wavelength range. We focus in particular on new generations of electrically driven QD single photon source leading to high repetition rates, strong coupling regime, and high collection efficiencies at elevated temperature operation. Besides, new developments of room temperature single photon emission in the strong coupling regime are reviewed. The generation of indistinguishable photons and remaining challenges for practical single-photon sources are also discussed.

  16. Single Photon Holographic Qudit Elements for Linear Optical Quantum Computing

    DTIC Science & Technology

    2011-05-01

    in optical volume holography and designed and simulated practical single-photon, single-optical elements for qudit MUB-state quantum in- formation...Independent of the representation we use, the MUB states will ordinarily be modulated in both amplitude and phase. Recently a practical method has been...quantum computing with qudits (d ≥ 3) has been an efficient and practical quantum state sorter for photons whose complex fields are modulated in both

  17. Investigating and Improving Student Understanding of Quantum Mechanics in the Context of Single Photon Interference

    ERIC Educational Resources Information Center

    Marshman, Emily; Singh, Chandralekha

    2017-01-01

    Single photon experiments involving a Mach-Zehnder interferometer can illustrate the fundamental principles of quantum mechanics, e.g., the wave-particle duality of a single photon, single photon interference, and the probabilistic nature of quantum measurement involving single photons. These experiments explicitly make the connection between the…

  18. Single-Atom Single-Photon Quantum Interface

    NASA Astrophysics Data System (ADS)

    Moehring, David; Bochmann, Joerg; Muecke, Martin; Specht, Holger; Weber, Bernhard; Wilk, Tatjana; Rempe, Gerhard

    2008-05-01

    By combining atom trapping techniques and cavity cooling schemes we are able to trap a single neutral atom inside a high-finesse cavity for several tens of seconds. We show that our coupled atom-cavity system can be used to generate single photons in a controlled way. With our long trapping times and high single-photon production efficiency, the non-classical properties of the emitted light can be shown in the photon correlations of a single atom. In a similar atom-cavity setup, we investigate the interface between atoms and photons by entangling a single atom with a single photon emitted into the cavity and by further mapping the quantum state of the atom onto a second single photon. These schemes are intrinsically deterministic and establish the basic element required to realize a distributed quantum network with individual atoms at rest as quantum memories and single flying photons as quantum messengers. This work was supported by the Deutsche Forschungsgemeinschaft, and the European Union SCALA and CONQUEST programs. D. L. M. acknowledges support from the Alexander von Humboldt Foundation.

  19. Single-photon transistor in circuit quantum electrodynamics.

    PubMed

    Neumeier, Lukas; Leib, Martin; Hartmann, Michael J

    2013-08-09

    We introduce a circuit quantum electrodynamical setup for a "single-photon" transistor. In our approach photons propagate in two open transmission lines that are coupled via two interacting transmon qubits. The interaction is such that no photons are exchanged between the two transmission lines but a single photon in one line can completely block or enable the propagation of photons in the other line. High on-off ratios can be achieved for feasible experimental parameters. Our approach is inherently scalable as all photon pulses can have the same pulse shape and carrier frequency such that output signals of one transistor can be input signals for a consecutive transistor.

  20. Quantum Probability Cancellation Due to a Single-Photon State

    NASA Technical Reports Server (NTRS)

    Ou, Z. Y.

    1996-01-01

    When an N-photon state enters a lossless symmetric beamsplitter from one input port, the photon distribution for the two output ports has the form of Bernouli Binormial, with highest probability at equal partition (N/2 at one outport and N/2 at the other). However, injection of a single photon state at the other input port can dramatically change the photon distribution at the outputs, resulting in zero probability at equal partition. Such a strong deviation from classical particle theory stems from quantum probability amplitude cancellation. The effect persists even if the N-photon state is replaced by an arbitrary state of light. A special case is the coherent state which corresponds to homodyne detection of a single photon state and can lead to the measurement of the wave function of a single photon state.

  1. Authenticated Quantum Key Distribution with Collective Detection using Single Photons

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Xu, Bing-Jie; Duan, Ji-Tong; Liu, Bin; Su, Qi; He, Yuan-Hang; Jia, Heng-Yue

    2016-10-01

    We present two authenticated quantum key distribution (AQKD) protocols by utilizing the idea of collective (eavesdropping) detection. One is a two-party AQKD protocol, the other is a multiparty AQKD protocol with star network topology. In these protocols, the classical channels need not be assumed to be authenticated and the single photons are used as the quantum information carriers. To achieve mutual identity authentication and establish a random key in each of the proposed protocols, only one participant should be capable of preparing and measuring single photons, and the main quantum ability that the rest of the participants should have is just performing certain unitary operations. Security analysis shows that these protocols are free from various kinds of attacks, especially the impersonation attack and the man-in-the-middle (MITM) attack.

  2. Quantum private query based on single-photon interference

    NASA Astrophysics Data System (ADS)

    Xu, Sheng-Wei; Sun, Ying; Lin, Song

    2016-08-01

    Quantum private query (QPQ) has become a research hotspot recently. Specially, the quantum key distribution (QKD)-based QPQ attracts lots of attention because of its practicality. Various such kind of QPQ protocols have been proposed based on different technologies of quantum communications. Single-photon interference is one of such technologies, on which the famous QKD protocol GV95 is just based. In this paper, we propose two QPQ protocols based on single-photon interference. The first one is simpler and easier to realize, and the second one is loss tolerant and flexible, and more practical than the first one. Furthermore, we analyze both the user privacy and the database privacy in the proposed protocols.

  3. Transform-limited single photons from a single quantum dot

    NASA Astrophysics Data System (ADS)

    Kuhlmann, Andreas V.; Prechtel, Jonathan H.; Houel, Julien; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D.; Warburton, Richard J.

    2015-09-01

    Developing a quantum photonics network requires a source of very-high-fidelity single photons. An outstanding challenge is to produce a transform-limited single-photon emitter to guarantee that single photons emitted far apart in the time domain are truly indistinguishable. This is particularly difficult in the solid-state as the complex environment is the source of noise over a wide bandwidth. A quantum dot is a robust, fast, bright and narrow-linewidth emitter of single photons; layer-by-layer growth and subsequent nano-fabrication allow the electronic and photonic states to be engineered. This represents a set of features not shared by any other emitter but transform-limited linewidths have been elusive. Here, we report transform-limited linewidths measured on second timescales, primarily on the neutral exciton but also on the charged exciton close to saturation. The key feature is control of the nuclear spins, which dominate the exciton dephasing via the Overhauser field.

  4. Transform-limited single photons from a single quantum dot

    PubMed Central

    Kuhlmann, Andreas V.; Prechtel, Jonathan H.; Houel, Julien; Ludwig, Arne; Reuter, Dirk; Wieck, Andreas D.; Warburton, Richard J.

    2015-01-01

    Developing a quantum photonics network requires a source of very-high-fidelity single photons. An outstanding challenge is to produce a transform-limited single-photon emitter to guarantee that single photons emitted far apart in the time domain are truly indistinguishable. This is particularly difficult in the solid-state as the complex environment is the source of noise over a wide bandwidth. A quantum dot is a robust, fast, bright and narrow-linewidth emitter of single photons; layer-by-layer growth and subsequent nano-fabrication allow the electronic and photonic states to be engineered. This represents a set of features not shared by any other emitter but transform-limited linewidths have been elusive. Here, we report transform-limited linewidths measured on second timescales, primarily on the neutral exciton but also on the charged exciton close to saturation. The key feature is control of the nuclear spins, which dominate the exciton dephasing via the Overhauser field. PMID:26348157

  5. Single-Photon Generation With InAs Quantum Dots

    DTIC Science & Technology

    2007-11-02

    improved efficiencies [13] and photon state purities such that the mean wavepacket overlap between consecutive photons is as high as 0.8 [14]. The...shown schematically in figure 1(a). One or more InAs quantum dots, surrounded by a GaAs matrix , are embedded in a micropillar optical cavity. The...diagram of single-photon device, (b) scanning-electron microscope image of actual pillar structures; and (c) optical excitation scheme. density of

  6. Single-Photon Superradiance from a Quantum Dot

    NASA Astrophysics Data System (ADS)

    Tighineanu, Petru; Daveau, Raphaël S.; Lehmann, Tau B.; Beere, Harvey E.; Ritchie, David A.; Lodahl, Peter; Stobbe, Søren

    2016-04-01

    We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron and the hole comprising the exciton gives rise to an anharmonic spectrum, which we exploit to prepare the superradiant quantum state deterministically with a laser pulse. We observe a fivefold enhancement of the oscillator strength compared to conventional quantum dots. The enhancement is limited by the base temperature of our cryostat and may lead to oscillator strengths above 1000 from a single quantum emitter at optical frequencies.

  7. Quantum optics. All-optical routing of single photons by a one-atom switch controlled by a single photon.

    PubMed

    Shomroni, Itay; Rosenblum, Serge; Lovsky, Yulia; Bechler, Orel; Guendelman, Gabriel; Dayan, Barak

    2014-08-22

    The prospect of quantum networks, in which quantum information is carried by single photons in photonic circuits, has long been the driving force behind the effort to achieve all-optical routing of single photons. We realized a single-photon-activated switch capable of routing a photon from any of its two inputs to any of its two outputs. Our device is based on a single atom coupled to a fiber-coupled, chip-based microresonator. A single reflected control photon toggles the switch from high reflection (R ~ 65%) to high transmission (T ~ 90%), with an average of ~1.5 control photons per switching event (~3, including linear losses). No additional control fields are required. The control and target photons are both in-fiber and practically identical, making this scheme compatible with scalable architectures for quantum information processing. Copyright © 2014, American Association for the Advancement of Science.

  8. Optimised quantum hacking of superconducting nanowire single-photon detectors

    NASA Astrophysics Data System (ADS)

    Tanner, Michael G.; Makarov, Vadim; Hadfield, Robert H.

    2014-03-01

    We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack.

  9. Spectral properties of single photons from quantum emitters

    NASA Astrophysics Data System (ADS)

    Müller, Philipp; Tentrup, Tristan; Bienert, Marc; Morigi, Giovanna; Eschner, Jürgen

    2017-08-01

    Quantum networks require flying qubits that transfer information between the nodes. This may be implemented by means of single atoms (the nodes) that emit and absorb single photons (the flying qubits) and requires full control of photon absorption and emission by the individual emitters. In this paper, we theoretically characterize the wave packet of a photon emitted by a single atom undergoing a spontaneous Raman transition in a three-level scheme. We investigate several excitation schemes that are experimentally relevant and discuss control parameters that allow one to tailor the spectrum of the emitted photon wave packet.

  10. Optimised quantum hacking of superconducting nanowire single-photon detectors.

    PubMed

    Tanner, Michael G; Makarov, Vadim; Hadfield, Robert H

    2014-03-24

    We explore bright-light control of superconducting nanowire single-photon detectors (SNSPDs) in the shunted configuration (a practical measure to avoid latching). In an experiment, we simulate an illumination pattern the SNSPD would receive in a typical quantum key distribution system under hacking attack. We show that it effectively blinds and controls the SNSPD. The transient blinding illumination lasts for a fraction of a microsecond and produces several deterministic fake clicks during this time. This attack does not lead to elevated timing jitter in the spoofed output pulse, and hence does not introduce significant errors. Five different SNSPD chip designs were tested. We consider possible countermeasures to this attack.

  11. Multi-group dynamic quantum secret sharing with single photons

    NASA Astrophysics Data System (ADS)

    Liu, Hongwei; Ma, Haiqiang; Wei, Kejin; Yang, Xiuqing; Qu, Wenxiu; Dou, Tianqi; Chen, Yitian; Li, Ruixue; Zhu, Wu

    2016-07-01

    In this letter, we propose a novel scheme for the realization of single-photon dynamic quantum secret sharing between a boss and three dynamic agent groups. In our system, the boss can not only choose one of these three groups to share the secret with, but also can share two sets of independent keys with two groups without redistribution. Furthermore, the security of communication is enhanced by using a control mode. Compared with previous schemes, our scheme is more flexible and will contribute to a practical application.

  12. All-optical tailoring of single-photon spectra in a quantum-dot microcavity system

    NASA Astrophysics Data System (ADS)

    Breddermann, D.; Heinze, D.; Binder, R.; Zrenner, A.; Schumacher, S.

    2016-10-01

    Semiconductor quantum-dot cavity systems are promising sources for solid-state-based on-demand generation of single photons for quantum communication. Commonly, the spectral characteristics of the emitted single photon are fixed by system properties such as electronic transition energies and spectral properties of the cavity. In the present work we study cavity-enhanced single-photon generation from the quantum-dot biexciton through a partly stimulated nondegenerate two-photon emission. We show that frequency and linewidth of the single photon can be fully controlled by the stimulating laser pulse, ultimately allowing for efficient all-optical spectral shaping of the single photon.

  13. Spatially resolved single photon detection with a quantum sensor array

    PubMed Central

    Zagoskin, A. M.; Wilson, R. D.; Everitt, M.; Savel'ev, S.; Gulevich, D. R.; Allen, J.; Dubrovich, V. K.; Il'ichev, E.

    2013-01-01

    We propose a method of resolving a spatially coherent signal, which contains on average just a single photon, against the background of local noise at the same frequency. The method is based on detecting the signal simultaneously in several points more than a wavelength apart through the entangling interaction of the incoming photon with the quantum metamaterial sensor array. The interaction produces the spatially correlated quantum state of the sensor array, characterised by a collective observable (e.g., total magnetic moment), which is read out using a quantum nondemolition measurement. We show that the effects of local noise (e.g., fluctuations affecting the elements of the array) are suppressed relative to the signal from the spatially coherent field of the incoming photon as , where N is the number of array elements. The realisation of this approach in the microwave range would be especially useful and is within the reach of current experimental techniques. PMID:24322568

  14. Quantum Zeno switch for single-photon coherent transport

    SciTech Connect

    Zhou Lan; Yang, S.; Liu Yuxi; Sun, C. P.; Nori, Franco

    2009-12-15

    Using a dynamical quantum Zeno effect, we propose a general approach to control the coupling between a two-level system (TLS) and its surroundings, by modulating the energy-level spacing of the TLS with a high-frequency signal. We show that the TLS-surroundings interaction can be turned off when the ratio between the amplitude and the frequency of the modulating field is adjusted to be a zero of a Bessel function. The quantum Zeno effect of the TLS can also be observed by the vanishing of the photon reflection at these zeros. Based on these results, we propose a quantum switch to control the transport of a single photon in a one-dimensional waveguide. Our analytical results agree well with numerical results using Floquet theory.

  15. Interfacing single photons and single quantum dots with photonic nanostructures

    NASA Astrophysics Data System (ADS)

    Lodahl, Peter; Mahmoodian, Sahand; Stobbe, Søren

    2015-04-01

    Photonic nanostructures provide a means of tailoring the interaction between light and matter and the past decade has witnessed tremendous experimental and theoretical progress on this subject. In particular, the combination with semiconductor quantum dots has proven successful. This manuscript reviews quantum optics with excitons in single quantum dots embedded in photonic nanostructures. The ability to engineer the light-matter interaction strength in integrated photonic nanostructures enables a range of fundamental quantum-electrodynamics experiments on, e.g., spontaneous-emission control, modified Lamb shifts, and enhanced dipole-dipole interaction. Furthermore, highly efficient single-photon sources and giant photon nonlinearities may be implemented with immediate applications for photonic quantum-information processing. This review summarizes the general theoretical framework of photon emission including the role of dephasing processes and applies it to photonic nanostructures of current interest, such as photonic-crystal cavities and waveguides, dielectric nanowires, and plasmonic waveguides. The introduced concepts are generally applicable in quantum nanophotonics and apply to a large extent also to other quantum emitters, such as molecules, nitrogen vacancy centers, or atoms. Finally, the progress and future prospects of applications in quantum-information processing are considered.

  16. Lecture demonstrations of interference and quantum erasing with single photons

    NASA Astrophysics Data System (ADS)

    Dimitrova, T. L.; Weis, A.

    2009-07-01

    Single-photon interference is a beautiful manifestation of the wave-particle duality of light and the double-slit Gedankenexperiment is a standard lecture example for introducing quantum mechanical reality. Interference arises only if each photon can follow several (classical) paths from the source to the detector, and if one does not have the possibility to determine which specific path the photon has taken. Attaching a specific label to the photon traveling along a specific path destroys the interference. However, in some cases those labels can be erased from the photon between leaving the apparatus and being detected, by which interference can be restored, a phenomenon called quantum erasing. We present lecture demonstration experiments that illustrate the wave-particle duality of light and the phenomenon of quantum erasing. Both experiments are first shown with strong light and, in a second step, on a photon-by-photon basis. The smooth transition from the quantum to the classical case can be shown in real time by varying the incident light intensity.

  17. Polarization control of single photon quantum orbital angular momentum states.

    PubMed

    Nagali, E; Sciarrino, F; De Martini, F; Piccirillo, B; Karimi, E; Marrucci, L; Santamato, E

    2009-10-12

    The orbital angular momentum of photons, being defined in an infinite-dimensional discrete Hilbert space, offers a promising resource for high-dimensional quantum information protocols in quantum optics. The biggest obstacle to its wider use is presently represented by the limited set of tools available for its control and manipulation. Here, we introduce and test experimentally a series of simple optical schemes for the coherent transfer of quantum information from the polarization to the orbital angular momentum of single photons and vice versa. All our schemes exploit a newly developed optical device, the so-called "q-plate", which enables the manipulation of the photon orbital angular momentum driven by the polarization degree of freedom. By stacking several q-plates in a suitable sequence, one can also have access to higher-order angular momentum subspaces. In particular, we demonstrate the control of the orbital angular momentum m degree of freedom within the subspaces of |m| = 2h and |m| = 4h per photon.

  18. Characterization of a Spontaneous Parametric Downconversion Source for Use in Single Photon Tests of Quantum Mechanics

    NASA Astrophysics Data System (ADS)

    Alexander, Preston; McDonld, Jackson; Harrington, Jason; Smith, R. Seth

    2014-03-01

    During the past year, a quantum optics laboratory was constructed and tested at Francis Marion University. A spontaneous parametric downconversion source was used to create pairs of correlated photons for use in single photon tests of quantum mechanics. Photons from a spontaneous parametric downconversion source were detected with single photon counting modules that were purchased through the Advanced Laboratory Physics Association (ALPHA). The effect of pump polarization on the output intensity was studied. Coincidences between pairs of correlated photons were counted and plotted as a function of the angle between the single photon detectors, in order to perform a test of Conservation of Momentum. The laboratory will be used to perform single photon tests of quantum mechanics, including the Grangier experiment, single photon interference, quantum state measurement, and tests of local realism.

  19. Terahertz single-photon detectors based on quantum wells

    NASA Astrophysics Data System (ADS)

    Kajihara, Yusuke; Nakajima, Takashi; Wang, Zhihai; Komiyama, Susumu

    2013-04-01

    Semiconductor charge-sensitive infrared phototransistors (CSIPs) based on quantum wells are described. They are the only detectors that are able to count single photons in the terahertz region at present. In terms of the noise equivalent power (NEP), the detectors show experimental values of 7 × 10-20 W/Hz1/2, while theoretically expected values are even much lower. These NEP values are by several orders of magnitude lower than any other state-of-the-art highly sensitive detectors. In addition to the outstanding sensitivity, the detectors are featured by strong advantage of huge current responsivity (>1 × 105 A/W) and low output impedance (<10 kΩ). This excellent performance in the above has been obtained for λ = 12-28 μm. By introducing a modified scheme of detection (called "lateral-escape") along with an improved coupler structure (bowtie antenna), we have achieved similar excellent performance for 45 μm. The CSIP provides extremely promising detectors for a variety of applications covering a wide spectral range of 12-100 μm.

  20. Storing single photons emitted by a quantum memory on a highly excited Rydberg state.

    PubMed

    Distante, Emanuele; Farrera, Pau; Padrón-Brito, Auxiliadora; Paredes-Barato, David; Heinze, Georg; de Riedmatten, Hugues

    2017-01-19

    Strong interaction between two single photons is a long standing and important goal in quantum photonics. This would enable a new regime of nonlinear optics and unlock several applications in quantum information science, including photonic quantum gates and deterministic Bell-state measurements. In the context of quantum networks, it would be important to achieve interactions between single photons from independent photon pairs storable in quantum memories. So far, most experiments showing nonlinearities at the single-photon level have used weak classical input light. Here we demonstrate the storage and retrieval of a paired single photon emitted by an ensemble quantum memory in a strongly nonlinear medium based on highly excited Rydberg atoms. We show that nonclassical correlations between the two photons persist after retrieval from the Rydberg ensemble. Our result is an important step towards deterministic photon-photon interactions, and may enable deterministic Bell-state measurements with multimode quantum memories.

  1. Storing single photons emitted by a quantum memory on a highly excited Rydberg state

    PubMed Central

    Distante, Emanuele; Farrera, Pau; Padrón-Brito, Auxiliadora; Paredes-Barato, David; Heinze, Georg; de Riedmatten, Hugues

    2017-01-01

    Strong interaction between two single photons is a long standing and important goal in quantum photonics. This would enable a new regime of nonlinear optics and unlock several applications in quantum information science, including photonic quantum gates and deterministic Bell-state measurements. In the context of quantum networks, it would be important to achieve interactions between single photons from independent photon pairs storable in quantum memories. So far, most experiments showing nonlinearities at the single-photon level have used weak classical input light. Here we demonstrate the storage and retrieval of a paired single photon emitted by an ensemble quantum memory in a strongly nonlinear medium based on highly excited Rydberg atoms. We show that nonclassical correlations between the two photons persist after retrieval from the Rydberg ensemble. Our result is an important step towards deterministic photon–photon interactions, and may enable deterministic Bell-state measurements with multimode quantum memories. PMID:28102203

  2. Storing single photons emitted by a quantum memory on a highly excited Rydberg state

    NASA Astrophysics Data System (ADS)

    Distante, Emanuele; Farrera, Pau; Padrón-Brito, Auxiliadora; Paredes-Barato, David; Heinze, Georg; de Riedmatten, Hugues

    2017-01-01

    Strong interaction between two single photons is a long standing and important goal in quantum photonics. This would enable a new regime of nonlinear optics and unlock several applications in quantum information science, including photonic quantum gates and deterministic Bell-state measurements. In the context of quantum networks, it would be important to achieve interactions between single photons from independent photon pairs storable in quantum memories. So far, most experiments showing nonlinearities at the single-photon level have used weak classical input light. Here we demonstrate the storage and retrieval of a paired single photon emitted by an ensemble quantum memory in a strongly nonlinear medium based on highly excited Rydberg atoms. We show that nonclassical correlations between the two photons persist after retrieval from the Rydberg ensemble. Our result is an important step towards deterministic photon-photon interactions, and may enable deterministic Bell-state measurements with multimode quantum memories.

  3. Investigating and improving student understanding of quantum mechanics in the context of single photon interference

    NASA Astrophysics Data System (ADS)

    Marshman, Emily; Singh, Chandralekha

    2017-06-01

    Single photon experiments involving a Mach-Zehnder interferometer can illustrate the fundamental principles of quantum mechanics, e.g., the wave-particle duality of a single photon, single photon interference, and the probabilistic nature of quantum measurement involving single photons. These experiments explicitly make the connection between the abstract quantum theory and concrete laboratory settings and have the potential to help students develop a solid grasp of the foundational issues in quantum mechanics. Here we describe students' conceptual difficulties with these topics in the context of Mach-Zehnder interferometer experiments with single photons and how the difficulties found in written surveys and individual interviews were used as a guide in the development of a Quantum Interactive Learning Tutorial (QuILT). The QuILT uses an inquiry-based approach to learning and takes into account the conceptual difficulties found via research to help upper-level undergraduate and graduate students learn about foundational quantum mechanics concepts using the concrete quantum optics context. It strives to help students learn the basics of quantum mechanics in the context of single photon experiment, develop the ability to apply fundamental quantum principles to experimental situations in quantum optics, and explore the differences between classical and quantum ideas in a concrete context. We discuss the findings from in-class evaluations suggesting that the QuILT was effective in helping students learn these abstract concepts.

  4. Quantum State Transfer from a Single Photon to a Distant Quantum-Dot Electron Spin.

    PubMed

    He, Yu; He, Yu-Ming; Wei, Yu-Jia; Jiang, Xiao; Chen, Kai; Lu, Chao-Yang; Pan, Jian-Wei; Schneider, Christian; Kamp, Martin; Höfling, Sven

    2017-08-11

    Quantum state transfer from flying photons to stationary matter qubits is an important element in the realization of quantum networks. Self-assembled semiconductor quantum dots provide a promising solid-state platform hosting both single photon and spin, with an inherent light-matter interface. Here, we develop a method to coherently and actively control the single-photon frequency bins in superposition using electro-optic modulators, and measure the spin-photon entanglement with a fidelity of 0.796±0.020. Further, by Greenberger-Horne-Zeilinger-type state projection on the frequency, path, and polarization degrees of freedom of a single photon, we demonstrate quantum state transfer from a single photon to a single electron spin confined in an InGaAs quantum dot, separated by 5 m. The quantum state mapping from the photon's polarization to the electron's spin is demonstrated along three different axes on the Bloch sphere, with an average fidelity of 78.5%.

  5. Quantum State Transfer from a Single Photon to a Distant Quantum-Dot Electron Spin

    NASA Astrophysics Data System (ADS)

    He, Yu; He, Yu-Ming; Wei, Yu-Jia; Jiang, Xiao; Chen, Kai; Lu, Chao-Yang; Pan, Jian-Wei; Schneider, Christian; Kamp, Martin; Höfling, Sven

    2017-08-01

    Quantum state transfer from flying photons to stationary matter qubits is an important element in the realization of quantum networks. Self-assembled semiconductor quantum dots provide a promising solid-state platform hosting both single photon and spin, with an inherent light-matter interface. Here, we develop a method to coherently and actively control the single-photon frequency bins in superposition using electro-optic modulators, and measure the spin-photon entanglement with a fidelity of 0.796 ±0.020 . Further, by Greenberger-Horne-Zeilinger-type state projection on the frequency, path, and polarization degrees of freedom of a single photon, we demonstrate quantum state transfer from a single photon to a single electron spin confined in an InGaAs quantum dot, separated by 5 m. The quantum state mapping from the photon's polarization to the electron's spin is demonstrated along three different axes on the Bloch sphere, with an average fidelity of 78.5%.

  6. Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors.

    PubMed

    Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko

    2015-09-25

    Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks.

  7. Dissipation-enabled efficient excitation transfer from a single photon to a single quantum emitter

    NASA Astrophysics Data System (ADS)

    Trautmann, N.; Alber, G.

    2016-05-01

    We propose a scheme for triggering a dissipation-dominated highly efficient excitation transfer from a single-photon wave packet to a single quantum emitter. This single-photon-induced optical pumping turns dominant dissipative processes, such as spontaneous photon emission by the emitter or cavity decay, into valuable tools for quantum information processing and quantum communication. It works for an arbitrarily shaped single-photon wave packet with sufficiently small bandwidth provided a matching condition is satisfied which balances the dissipative rates involved. Our scheme does not require additional laser pulses or quantum feedback and does not rely on high finesse optical resonators. In particular, it can be used to enhance significantly the coupling of a single photon to a single quantum emitter implanted in a one-dimensional waveguide or even in a free space scenario. We demonstrate the usefulness of our scheme for building a deterministic quantum memory and a deterministic frequency converter between photonic qubits of different wavelengths.

  8. Young's double-slit experiment with single photons and quantum eraser

    NASA Astrophysics Data System (ADS)

    Rueckner, Wolfgang; Peidle, Joseph

    2013-12-01

    An apparatus for a double-slit interference experiment in the single-photon regime is described. The apparatus includes a which-path marker that destroys the interference as well as a quantum eraser that restores it. We present data taken with several light sources, coherent and incoherent and discuss the efficacy of these as sources of single photons.

  9. Single-photon three-qubit quantum logic using spatial light modulators.

    PubMed

    Kagalwala, Kumel H; Di Giuseppe, Giovanni; Abouraddy, Ayman F; Saleh, Bahaa E A

    2017-09-29

    The information-carrying capacity of a single photon can be vastly expanded by exploiting its multiple degrees of freedom: spatial, temporal, and polarization. Although multiple qubits can be encoded per photon, to date only two-qubit single-photon quantum operations have been realized. Here, we report an experimental demonstration of three-qubit single-photon, linear, deterministic quantum gates that exploit photon polarization and the two-dimensional spatial-parity-symmetry of the transverse single-photon field. These gates are implemented using a polarization-sensitive spatial light modulator that provides a robust, non-interferometric, versatile platform for implementing controlled unitary gates. Polarization here represents the control qubit for either separable or entangling unitary operations on the two spatial-parity target qubits. Such gates help generate maximally entangled three-qubit Greenberger-Horne-Zeilinger and W states, which is confirmed by tomographical reconstruction of single-photon density matrices. This strategy provides access to a wide range of three-qubit states and operations for use in few-qubit quantum information processing protocols.Photons are essential for quantum information processing, but to date only two-qubit single-photon operations have been realized. Here the authors demonstrate experimentally a three-qubit single-photon linear deterministic quantum gate by exploiting polarization along with spatial-parity symmetry.

  10. Single-photon filtering by a cavity quantum electrodynamics system

    SciTech Connect

    Koshino, Kazuki

    2008-02-15

    The nonlinear dynamics of a classical photon pulse in a cavity-QED system is investigated theoretically. It is shown that this system can work as a single-photon filter, which drastically suppresses the multiple-photon probability of the output. The output photon statistics is sensitive to the input pulse length. A suitable choice of pulse length produces a photon pulse with the single-photon probability of 0.32, while the multiple-photon probability is suppressed to 0.01.

  11. Elliptical quantum dots as on-demand single photons sources with deterministic polarization states

    SciTech Connect

    Teng, Chu-Hsiang; Demory, Brandon; Ku, Pei-Cheng; Zhang, Lei; Hill, Tyler A.; Deng, Hui

    2015-11-09

    In quantum information, control of the single photon's polarization is essential. Here, we demonstrate single photon generation in a pre-programmed and deterministic polarization state, on a chip-scale platform, utilizing site-controlled elliptical quantum dots (QDs) synthesized by a top-down approach. The polarization from the QD emission is found to be linear with a high degree of linear polarization and parallel to the long axis of the ellipse. Single photon emission with orthogonal polarizations is achieved, and the dependence of the degree of linear polarization on the QD geometry is analyzed.

  12. Single photon delayed feedback: a way to stabilize intrinsic quantum cavity electrodynamics.

    PubMed

    Carmele, Alexander; Kabuss, Julia; Schulze, Franz; Reitzenstein, Stephan; Knorr, Andreas

    2013-01-04

    We propose a scheme to control cavity quantum electrodynamics in the single photon limit by delayed feedback. In our approach a single emitter-cavity system, operating in the weak coupling limit, can be driven into the strong coupling-type regime by an external mirror: The external loop produces Rabi oscillations directly connected to the electron-photon coupling strength. As an expansion of typical cavity quantum electrodynamics, we treat the quantum correlation of external and internal light modes dynamically and demonstrate a possible way to implement a fully quantum mechanical time-delayed feedback. Our theoretical approach proposes a way to experimentally feedback control quantum correlations in the single photon limit.

  13. Downconversion quantum interface for a single quantum dot spin and 1550-nm single-photon channel.

    PubMed

    Pelc, Jason S; Yu, Leo; De Greve, Kristiaan; McMahon, Peter L; Natarajan, Chandra M; Esfandyarpour, Vahid; Maier, Sebastian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Hadfield, Robert H; Forchel, Alfred; Yamamoto, Yoshihisa; Fejer, M M

    2012-12-03

    Long-distance quantum communication networks require appropriate interfaces between matter qubit-based nodes and low-loss photonic quantum channels. We implement a downconversion quantum interface, where the single photons emitted from a semiconductor quantum dot at 910 nm are downconverted to 1560 nm using a fiber-coupled periodically poled lithium niobate waveguide and a 2.2-μm pulsed pump laser. The single-photon character of the quantum dot emission is preserved during the downconversion process: we measure a cross-correlation g(2)(τ = 0) = 0.17 using resonant excitation of the quantum dot. We show that the downconversion interface is fully compatible with coherent optical control of the quantum dot electron spin through the observation of Rabi oscillations in the downconverted photon counts. These results represent a critical step towards a long-distance hybrid quantum network in which subsystems operating at different wavelengths are connected through quantum frequency conversion devices and 1.5-μm quantum channels.

  14. Quantum routing of single photons with a cyclic three-level system.

    PubMed

    Zhou, Lan; Yang, Li-Ping; Li, Yong; Sun, C P

    2013-09-06

    We propose an experimentally accessible single-photon routing scheme using a △-type three-level atom embedded in quantum multichannels composed of coupled-resonator waveguides. Via the on-demand classical field being applied to the atom, the router can extract a single photon from the incident channel, and then redirect it into another. The efficient function of the perfect reflection of the single-photon signal in the incident channel is rooted in the coherent resonance and the existence of photonic bound states.

  15. Ultrafast room temperature single-photon source from nanowire-quantum dots.

    PubMed

    Bounouar, S; Elouneg-Jamroz, M; Hertog, M den; Morchutt, C; Bellet-Amalric, E; André, R; Bougerol, C; Genuist, Y; Poizat, J-Ph; Tatarenko, S; Kheng, K

    2012-06-13

    Epitaxial semiconductor quantum dots are particularly promising as realistic single-photon sources for their compatibility with manufacturing techniques and possibility to be implemented in compact devices. Here, we demonstrate for the first time single-photon emission up to room temperature from an epitaxial quantum dot inserted in a nanowire, namely a CdSe slice in a ZnSe nanowire. The exciton and biexciton lines can still be resolved at room temperature and the biexciton turns out to be the most appropriate transition for single-photon emission due to a large nonradiative decay of the bright exciton to dark exciton states. With an intrinsically short radiative decay time (≈300 ps) this system is the fastest room temperature single-photon emitter, allowing potentially gigahertz repetition rates.

  16. Improving the performance of bright quantum dot single photon sources using temporal filtering via amplitude modulation.

    PubMed

    Ates, Serkan; Agha, Imad; Gulinatti, Angelo; Rech, Ivan; Badolato, Antonio; Srinivasan, Kartik

    2013-01-01

    Single epitaxially-grown semiconductor quantum dots have great potential as single photon sources for photonic quantum technologies, though in practice devices often exhibit nonideal behavior. Here, we demonstrate that amplitude modulation can improve the performance of quantum-dot-based sources. Starting with a bright source consisting of a single quantum dot in a fiber-coupled microdisk cavity, we use synchronized amplitude modulation to temporally filter the emitted light. We observe that the single photon purity, temporal overlap between successive emission events, and indistinguishability can be greatly improved with this technique. As this method can be applied to any triggered single photon source, independent of geometry and after device fabrication, it is a flexible approach to improve the performance of systems based on single solid-state quantum emitters, which often suffer from excess dephasing and multi-photon background emission.

  17. Improving the performance of bright quantum dot single photon sources using temporal filtering via amplitude modulation

    PubMed Central

    Ates, Serkan; Agha, Imad; Gulinatti, Angelo; Rech, Ivan; Badolato, Antonio; Srinivasan, Kartik

    2013-01-01

    Single epitaxially-grown semiconductor quantum dots have great potential as single photon sources for photonic quantum technologies, though in practice devices often exhibit nonideal behavior. Here, we demonstrate that amplitude modulation can improve the performance of quantum-dot-based sources. Starting with a bright source consisting of a single quantum dot in a fiber-coupled microdisk cavity, we use synchronized amplitude modulation to temporally filter the emitted light. We observe that the single photon purity, temporal overlap between successive emission events, and indistinguishability can be greatly improved with this technique. As this method can be applied to any triggered single photon source, independent of geometry and after device fabrication, it is a flexible approach to improve the performance of systems based on single solid-state quantum emitters, which often suffer from excess dephasing and multi-photon background emission. PMID:23466520

  18. Ultrafast single photon emitting quantum photonic structures based on a nano-obelisk

    PubMed Central

    Kim, Je-Hyung; Ko, Young-Ho; Gong, Su-Hyun; Ko, Suk-Min; Cho, Yong-Hoon

    2013-01-01

    A key issue in a single photon source is fast and efficient generation of a single photon flux with high light extraction efficiency. Significant progress toward high-efficiency single photon sources has been demonstrated by semiconductor quantum dots, especially using narrow bandgap materials. Meanwhile, there are many obstacles, which restrict the use of wide bandgap semiconductor quantum dots as practical single photon sources in ultraviolet-visible region, despite offering free space communication and miniaturized quantum information circuits. Here we demonstrate a single InGaN quantum dot embedded in an obelisk-shaped GaN nanostructure. The nano-obelisk plays an important role in eliminating dislocations, increasing light extraction, and minimizing a built-in electric field. Based on the nano-obelisks, we observed nonconventional narrow quantum dot emission and positive biexciton binding energy, which are signatures of negligible built-in field in single InGaN quantum dots. This results in efficient and ultrafast single photon generation in the violet color region. PMID:23828558

  19. Ultrafast single photon emitting quantum photonic structures based on a nano-obelisk

    NASA Astrophysics Data System (ADS)

    Kim, Je-Hyung; Ko, Young-Ho; Gong, Su-Hyun; Ko, Suk-Min; Cho, Yong-Hoon

    2013-07-01

    A key issue in a single photon source is fast and efficient generation of a single photon flux with high light extraction efficiency. Significant progress toward high-efficiency single photon sources has been demonstrated by semiconductor quantum dots, especially using narrow bandgap materials. Meanwhile, there are many obstacles, which restrict the use of wide bandgap semiconductor quantum dots as practical single photon sources in ultraviolet-visible region, despite offering free space communication and miniaturized quantum information circuits. Here we demonstrate a single InGaN quantum dot embedded in an obelisk-shaped GaN nanostructure. The nano-obelisk plays an important role in eliminating dislocations, increasing light extraction, and minimizing a built-in electric field. Based on the nano-obelisks, we observed nonconventional narrow quantum dot emission and positive biexciton binding energy, which are signatures of negligible built-in field in single InGaN quantum dots. This results in efficient and ultrafast single photon generation in the violet color region.

  20. Ultrafast single photon emitting quantum photonic structures based on a nano-obelisk.

    PubMed

    Kim, Je-Hyung; Ko, Young-Ho; Gong, Su-Hyun; Ko, Suk-Min; Cho, Yong-Hoon

    2013-01-01

    A key issue in a single photon source is fast and efficient generation of a single photon flux with high light extraction efficiency. Significant progress toward high-efficiency single photon sources has been demonstrated by semiconductor quantum dots, especially using narrow bandgap materials. Meanwhile, there are many obstacles, which restrict the use of wide bandgap semiconductor quantum dots as practical single photon sources in ultraviolet-visible region, despite offering free space communication and miniaturized quantum information circuits. Here we demonstrate a single InGaN quantum dot embedded in an obelisk-shaped GaN nanostructure. The nano-obelisk plays an important role in eliminating dislocations, increasing light extraction, and minimizing a built-in electric field. Based on the nano-obelisks, we observed nonconventional narrow quantum dot emission and positive biexciton binding energy, which are signatures of negligible built-in field in single InGaN quantum dots. This results in efficient and ultrafast single photon generation in the violet color region.

  1. Temporal Purity and Quantum Interference of Single Photons from Two Independent Cold Atomic Ensembles

    NASA Astrophysics Data System (ADS)

    Qian, Peng; Gu, Zhenjie; Cao, Rong; Wen, Rong; Ou, Z. Y.; Chen, J. F.; Zhang, Weiping

    2016-07-01

    The temporal purity of single photons is crucial to the indistinguishability of independent photon sources for the fundamental study of the quantum nature of light and the development of photonic technologies. Currently, the technique for single photons heralded from time-frequency entangled biphotons created in nonlinear crystals does not guarantee the temporal-quantum purity, except using spectral filtering. Nevertheless, an entirely different situation is anticipated for narrow-band biphotons with a coherence time far longer than the time resolution of a single-photon detector. Here we demonstrate temporally pure single photons with a coherence time of 100 ns, directly heralded from the time-frequency entangled biphotons generated by spontaneous four-wave mixing in cold atomic ensembles, without any supplemented filters or cavities. A near-perfect purity and indistinguishability are both verified through Hong-Ou-Mandel quantum interference using single photons from two independent cold atomic ensembles. The time-frequency entanglement provides a route to manipulate the pure temporal state of the single-photon source.

  2. Calibration of single-photon detectors using quantum statistics

    SciTech Connect

    Mogilevtsev, D.

    2010-08-15

    I show that calibration of the single-photon detector can be performed without knowledge of the signal parameters. Only partial information about the state statistics is sufficient for that. If one knows that the state is the squeezed one or the squeezed one mixed with the incoherent radiation, one can infer both the parameters of the state and the efficiency of the detector. For that one needs only to measure on/off statistics of detector clicks for the number of known absorbers placed before the detector. Thus, I suggest a scheme that performs a tomography of the signal and the measuring apparatus simultaneously.

  3. Research on Electrically Driven Single Photon Emitter by Diamond for Quantum Cryptography

    DTIC Science & Technology

    2015-03-24

    by diamond for quantum cryptography 5a. CONTRACT NUMBER FA2386-14-1-4037 5b. GRANT NUMBE R Grant 14IOA093_144037 5c. PROGRAM ELEMENT...emerged as a highly competitive platform for applications in quantum cryptography , quantum computing, spintronics, and sensing or metrology...15. SUBJECT TERMS Diamond LED, Nitrogen Vacancy Complex, Quantum Computing, Quantum Cryptography , Single Spin Single Photon 16. SECURITY

  4. Simple Atomic Quantum Memory Suitable for Semiconductor Quantum Dot Single Photons

    NASA Astrophysics Data System (ADS)

    Wolters, Janik; Buser, Gianni; Horsley, Andrew; Béguin, Lucas; Jöckel, Andreas; Jahn, Jan-Philipp; Warburton, Richard J.; Treutlein, Philipp

    2017-08-01

    Quantum memories matched to single photon sources will form an important cornerstone of future quantum network technology. We demonstrate such a memory in warm Rb vapor with on-demand storage and retrieval, based on electromagnetically induced transparency. With an acceptance bandwidth of δ f =0.66 GHz , the memory is suitable for single photons emitted by semiconductor quantum dots. In this regime, vapor cell memories offer an excellent compromise between storage efficiency, storage time, noise level, and experimental complexity, and atomic collisions have negligible influence on the optical coherences. Operation of the memory is demonstrated using attenuated laser pulses on the single photon level. For a 50 ns storage time, we measure ηe2 e 50 ns=3.4 (3 )% end-to-end efficiency of the fiber-coupled memory, with a total intrinsic efficiency ηint=17 (3 )%. Straightforward technological improvements can boost the end-to-end-efficiency to ηe 2 e≈35 %; beyond that, increasing the optical depth and exploiting the Zeeman substructure of the atoms will allow such a memory to approach near unity efficiency. In the present memory, the unconditional read-out noise level of 9 ×10-3 photons is dominated by atomic fluorescence, and for input pulses containing on average μ1=0.27 (4 ) photons, the signal to noise level would be unity.

  5. Quantum-confined single photon emission at room temperature from SiC tetrapods.

    PubMed

    Castelletto, Stefania; Bodrog, Zoltán; Magyar, Andrew P; Gentle, Angus; Gali, Adam; Aharonovich, Igor

    2014-09-07

    Controlled engineering of isolated solid state quantum systems is one of the most prominent goals in modern nanotechnology. In this letter we demonstrate a previously unknown quantum system namely silicon carbide tetrapods. The tetrapods have a cubic polytype core (3C) and hexagonal polytype legs (4H)--a geometry that creates spontaneous polarization within a single tetrapod. Modeling of the tetrapod structures predicts that a bound exciton should exist at the 3C-4H interface. The simulations are confirmed by the observation of fully polarized and narrowband single photon emission from the tetrapods at room temperature. The single photon emission provides important insights into understanding the quantum confinement effects in non-spherical nanostructures. Our results pave the way to a new class of crystal phase nanomaterials that exhibit single photon emission at room temperature and therefore are suitable for sensing, quantum information and nanophotonics.

  6. Quantum interference between two single photons emitted by independently trapped atoms.

    PubMed

    Beugnon, J; Jones, M P A; Dingjan, J; Darquié, B; Messin, G; Browaeys, A; Grangier, P

    2006-04-06

    When two indistinguishable single photons are fed into the two input ports of a beam splitter, the photons will coalesce and leave together from the same output port. This is a quantum interference effect, which occurs because two possible paths-in which the photons leave by different output ports-interfere destructively. This effect was first observed in parametric downconversion (in which a nonlinear crystal splits a single photon into two photons of lower energy), then from two separate downconversion crystals, as well as with single photons produced one after the other by the same quantum emitter. With the recent developments in quantum information research, much attention has been devoted to this interference effect as a resource for quantum data processing using linear optics techniques. To ensure the scalability of schemes based on these ideas, it is crucial that indistinguishable photons are emitted by a collection of synchronized, but otherwise independent sources. Here we demonstrate the quantum interference of two single photons emitted by two independently trapped single atoms, bridging the gap towards the simultaneous emission of many indistinguishable single photons by different emitters. Our data analysis shows that the observed coalescence is mainly limited by wavefront matching of the light emitted by the two atoms, and to a lesser extent by the motion of each atom in its own trap.

  7. Quantum-confined single photon emission at room temperature from SiC tetrapods

    NASA Astrophysics Data System (ADS)

    Castelletto, Stefania; Bodrog, Zoltán; Magyar, Andrew P.; Gentle, Angus; Gali, Adam; Aharonovich, Igor

    2014-08-01

    Controlled engineering of isolated solid state quantum systems is one of the most prominent goals in modern nanotechnology. In this letter we demonstrate a previously unknown quantum system namely silicon carbide tetrapods. The tetrapods have a cubic polytype core (3C) and hexagonal polytype legs (4H) - a geometry that creates spontaneous polarization within a single tetrapod. Modeling of the tetrapod structures predicts that a bound exciton should exist at the 3C-4H interface. The simulations are confirmed by the observation of fully polarized and narrowband single photon emission from the tetrapods at room temperature. The single photon emission provides important insights into understanding the quantum confinement effects in non-spherical nanostructures. Our results pave the way to a new class of crystal phase nanomaterials that exhibit single photon emission at room temperature and therefore are suitable for sensing, quantum information and nanophotonics.Controlled engineering of isolated solid state quantum systems is one of the most prominent goals in modern nanotechnology. In this letter we demonstrate a previously unknown quantum system namely silicon carbide tetrapods. The tetrapods have a cubic polytype core (3C) and hexagonal polytype legs (4H) - a geometry that creates spontaneous polarization within a single tetrapod. Modeling of the tetrapod structures predicts that a bound exciton should exist at the 3C-4H interface. The simulations are confirmed by the observation of fully polarized and narrowband single photon emission from the tetrapods at room temperature. The single photon emission provides important insights into understanding the quantum confinement effects in non-spherical nanostructures. Our results pave the way to a new class of crystal phase nanomaterials that exhibit single photon emission at room temperature and therefore are suitable for sensing, quantum information and nanophotonics. Electronic supplementary information (ESI) available

  8. Polarisation-controlled single photon emission at high temperatures from InGaN quantum dots.

    PubMed

    Wang, T; Puchtler, T J; Zhu, T; Jarman, J C; Nuttall, L P; Oliver, R A; Taylor, R A

    2017-07-13

    Solid-state single photon sources with polarisation control operating beyond the Peltier cooling barrier of 200 K are desirable for a variety of applications in quantum technology. Using a non-polar InGaN system, we report the successful realisation of single photon emission with a g((2))(0) of 0.21, a high polarisation degree of 0.80, a fixed polarisation axis determined by the underlying crystallography, and a GHz repetition rate with a radiative lifetime of 357 ps at 220 K in semiconductor quantum dots. The temperature insensitivity of these properties, together with the simple planar epitaxial growth method and absence of complex device geometries, demonstrates that fast single photon emission with polarisation control can be achieved in solid-state quantum dots above the Peltier temperature threshold, making this system a potential candidate for future on-chip applications in integrated systems.

  9. Conversion from Single Photon to Single Electron Spin Using Electrically Controllable Quantum Dots

    NASA Astrophysics Data System (ADS)

    Oiwa, Akira; Fujita, Takafumi; Kiyama, Haruki; Allison, Giles; Ludwig, Arne; Wieck, Andreas D.; Tarucha, Seigo

    2017-01-01

    Polarization is a fundamental property of light and could provide various solutions to the development of secure optical communications with high capacity and high speed. In particular, the coherent quantum state conversion between single photons and single electron spins is a prerequisite for long-distance quantum communications and distributed quantum computation. Electrically defined quantum dots have already been proven to be suitable for scalable solid state qubits by demonstrations of single-spin coherent manipulations and two-qubit gate operations. Thus, their capacity for quantum information technologies would be considerably extended by the achievement of entanglement between an electron spin in the quantum dots and a photon. In this review paper, we show the basic technologies for trapping single electrons generated by single photons in quantum dots and for detecting their spins using the Pauli effect with sensitive charge sensors.

  10. Differential-phase-shift quantum key distribution using heralded narrow-band single photons.

    PubMed

    Liu, Chang; Zhang, Shanchao; Zhao, Luwei; Chen, Peng; Fung, C-H F; Chau, H F; Loy, M M T; Du, Shengwang

    2013-04-22

    We demonstrate the first proof of principle differential phase shift (DPS) quantum key distribution (QKD) using narrow-band heralded single photons with amplitude-phase modulations. In the 3-pulse case, we obtain a quantum bit error rate (QBER) as low as 3.06% which meets the unconditional security requirement. As we increase the pulse number up to 15, the key creation efficiency approaches 93.4%, but with a cost of increasing the QBER. Our result suggests that narrow-band single photons maybe a promising source for the DPS-QKD protocol.

  11. Quantum teleportation through an entangled state composed of displaced vacuum and single-photon states

    SciTech Connect

    Podoshvedov, S. A.

    2008-03-15

    We study a teleportation protocol of an unknown macroscopic qubit by means of a quantum channel composed of the displaced vacuum and single-photon states. The scheme is based on linear optical devices such as a beam splitter and photon number resolving detectors. A method based on conditional measurement is used to generate both the macroscopic qubit and entangled state composed from displaced vacuum and single-photon states. We show that such a qubit has both macroscopic and microscopic properties. In particular, we investigate a quantum teleportation protocol from a macroscopic object to a microscopic state.

  12. Single photon transport in two waveguides chirally coupled by a quantum emitter.

    PubMed

    Cheng, Mu-Tian; Ma, Xiao-San; Zhang, Jia-Yan; Wang, Bing

    2016-08-22

    We investigate single photon transport in two waveguides coupled to a two-level quantum emitter (QE). With the deduced analytical scattering amplitudes, we show that under condition of the chiral coupling between the QE and the photon in the two waveguides, the QE can play the role of ideal quantum router to redirect a single photon incident from one waveguide into the other waveguide with a probability of 100% in the ideal condition. The influences of cross coupling between two waveguides and dissipations on the routing are also shown.

  13. Large ordered arrays of single photon sources based on II-VI semiconductor colloidal quantum dot.

    PubMed

    Zhang, Qiang; Dang, Cuong; Urabe, Hayato; Wang, Jing; Sun, Shouheng; Nurmikko, Arto

    2008-11-24

    In this paper, we developed a novel and efficient method of deterministically organizing colloidal particles on structured surfaces over macroscopic areas. Our approach utilizes integrated solution-based processes of dielectric encapsulation and electrostatic-force-mediated self-assembly, which allow precisely controlled placement of sub-10nm sized particles at single particle resolution. As a specific demonstration, motivated by application to single photon sources, highly ordered 2D arrays of single II-VI semiconductor colloidal quantum dots (QDs) were created by this method. Individually, the QDs display triggered single photon emission at room temperature with characteristic photon antibunching statistics, suggesting a pathway to scalable quantum optical radiative systems.

  14. Single-photon non-linear optics with a quantum dot in a waveguide

    PubMed Central

    Javadi, A.; Söllner, I.; Arcari, M.; Hansen, S. Lindskov; Midolo, L.; Mahmoodian, S.; Kiršanskė, G; Pregnolato, T.; Lee, E. H.; Song, J. D.; Stobbe, S.; Lodahl, P.

    2015-01-01

    Strong non-linear interactions between photons enable logic operations for both classical and quantum-information technology. Unfortunately, non-linear interactions are usually feeble and therefore all-optical logic gates tend to be inefficient. A quantum emitter deterministically coupled to a propagating mode fundamentally changes the situation, since each photon inevitably interacts with the emitter, and highly correlated many-photon states may be created. Here we show that a single quantum dot in a photonic-crystal waveguide can be used as a giant non-linearity sensitive at the single-photon level. The non-linear response is revealed from the intensity and quantum statistics of the scattered photons, and contains contributions from an entangled photon–photon bound state. The quantum non-linearity will find immediate applications for deterministic Bell-state measurements and single-photon transistors and paves the way to scalable waveguide-based photonic quantum-computing architectures. PMID:26492951

  15. Single-photon non-linear optics with a quantum dot in a waveguide.

    PubMed

    Javadi, A; Söllner, I; Arcari, M; Hansen, S Lindskov; Midolo, L; Mahmoodian, S; Kiršanskė, G; Pregnolato, T; Lee, E H; Song, J D; Stobbe, S; Lodahl, P

    2015-10-23

    Strong non-linear interactions between photons enable logic operations for both classical and quantum-information technology. Unfortunately, non-linear interactions are usually feeble and therefore all-optical logic gates tend to be inefficient. A quantum emitter deterministically coupled to a propagating mode fundamentally changes the situation, since each photon inevitably interacts with the emitter, and highly correlated many-photon states may be created. Here we show that a single quantum dot in a photonic-crystal waveguide can be used as a giant non-linearity sensitive at the single-photon level. The non-linear response is revealed from the intensity and quantum statistics of the scattered photons, and contains contributions from an entangled photon-photon bound state. The quantum non-linearity will find immediate applications for deterministic Bell-state measurements and single-photon transistors and paves the way to scalable waveguide-based photonic quantum-computing architectures.

  16. Tunable-correlation phenomenon of single photons emitted from a self-assembled quantum dot

    NASA Astrophysics Data System (ADS)

    Yu, Shang; Wang, Yi-Tao; Tang, Jian-Shun; Yu, Ying; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Han, Yong-Jian; Li, Chuan-Feng; Guo, Guang-Can

    2017-02-01

    Deterministic single-photon source plays a key role in the quantum information technology. Thus, research on various properties of such kind of light source becomes a quite necessary task. In this work, we experimentally observe that the second-order correlation properties of single photons can be continuously tuned from pulsed excitation configuration to continuous-wave excitation configuration under the near resonant photoluminescence excitation. By increasing the power of pulsed excitation laser, the effective excitation time of quantum dot can be extended with assistance of the defect states, and more continuous-wave excitation characteristics will gradually appear in the second-order correlation functions. This abnormal power-induced tunable-correlation mechanism can affect the temporal property of the single-photon source but maintain its antibunching property.

  17. Heralded single-photon sources for quantum-key-distribution applications

    NASA Astrophysics Data System (ADS)

    Schiavon, Matteo; Vallone, Giuseppe; Ticozzi, Francesco; Villoresi, Paolo

    2016-01-01

    Single-photon sources (SPSs) are a fundamental building block for optical implementations of quantum information protocols. Among SPSs, multiple crystal heralded single-photon sources seem to give the best compromise between high pair production rate and low multiple photon events. In this work, we study their performance in a practical quantum-key-distribution experiment, by evaluating the achievable key rates. The analysis focuses on the two different schemes, symmetric and asymmetric, proposed for the practical implementation of heralded single-photon sources, with attention on the performance of their composing elements. The analysis is based on the protocol proposed by Bennett and Brassard in 1984 and on its improvement exploiting decoy state technique. Finally, a simple way of exploiting the postselection mechanism for a passive, one decoy state scheme is evaluated.

  18. Single-Photon Secure Quantum Dialogue Protocol Without Information Leakage

    NASA Astrophysics Data System (ADS)

    Zhou, Nan-Run; Hua, Tian-Xiang; Wu, Gui-Tong; He, Chao-Sheng; Zhang, Ye

    2014-11-01

    Combining the idea of ping-pong protocol with Controlled-NOT operation, we propose a secure quantum dialogue protocol based on single-photonss. Bob obtains the information of the encrypted quantum state by performing Controlled-NOT operation on the auxiliary particle and the encrypted single-photonss. Unlike the previous quantum dialogue protocols based on single-photonss, the proposed protocol not only overcomes information leakage but also possesses an acceptable efficiency.

  19. Cavity-enhanced single photons from a quantum dot (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Vuckovic, Jelena; Fattal, David; Englund, Dirk; Waks, Edo; Santori, Charles; Solomon, Glenn; Yamamoto, Yoshihisa

    2005-04-01

    Single-photon sources rarely emit two or more photons in the same pulse, compared to a Poisson-distributed source of the same intensity, and have numerous applications in quantum information science. The quality of such a source is evaluated based on three criteria: high efficiency, small multi-photon probability, and quantum indistinguishability. We have demonstrated a single-photon source based on a quantum dot in a micropost microcavity that exhibits a large Purcell factor together with a small multi-photon probability. For a quantum dot on resonance with the cavity, the spontaneous emission rate has been increased by a factor of five, while the probability to emit two or more photons in the same pulse has been reduced to 2% compared to a Poisson-distributed source of the same intensity. The indistinguishability of emitted single photons from one of our devices has been tested through a Hong-Ou-Mandel-type two-photon interference experiment; consecutive photons emitted from such a source have been largely indistinguishable, with a mean wave-packet overlap as large as 0.81. We have also designed and demonstrated two-dimensional photonic crystal GaAs cavities containing InAs quantum dots that exhibit much higher quality factors together with much smaller mode volumes than microposts, and therefore present an ideal platform for construction of single photon sources of even higher quality.

  20. Generating single photons at gigahertz modulation-speed using electrically controlled quantum dot microlenses

    SciTech Connect

    Schlehahn, A.; Schmidt, R.; Hopfmann, C.; Schulze, J.-H.; Strittmatter, A.; Heindel, T. Reitzenstein, S.; Gantz, L.; Schmidgall, E. R.; Gershoni, D.

    2016-01-11

    We report on the generation of single-photon pulse trains at a repetition rate of up to 1 GHz. We achieve this speed by modulating the external voltage applied on an electrically contacted quantum dot microlens, which is optically excited by a continuous-wave laser. By modulating the photoluminescence of the quantum dot microlens using a square-wave voltage, single-photon emission is triggered with a response time as short as (281 ± 19) ps, being 6 times faster than the radiative lifetime of (1.75 ± 0.02) ns. This large reduction in the characteristic emission time is enabled by a rapid capacitive gating of emission from the quantum dot, which is placed in the intrinsic region of a p-i-n-junction biased below the onset of electroluminescence. Here, since our circuit acts as a rectifying differentiator, the rising edge of the applied voltage pulses triggers the emission of single photons from the optically excited quantum dot. The non-classical nature of the photon pulse train generated at GHz-speed is proven by intensity autocorrelation measurements with g{sup (2)}(0) = 0.3 ± 0.1. Our results combine optical excitation with fast electrical gating and thus show promise for the generation of indistinguishable single photons at rates exceeding the limitations set by the intrinsic radiative lifetime.

  1. Quantum teleportation of the angular spectrum of a single-photon field

    SciTech Connect

    Walborn, S. P.; Ether, D. S.; Matos Filho, R. L. de; Zagury, N.

    2007-09-15

    We propose a quantum teleportation scheme for the angular spectrum of a single-photon field, which allows for the transmission of a large amount of information. Our proposal also provides a method to tune the frequencies of spatially entangled fields, which is useful for interactions with stationary qubits.

  2. Generating single photons at gigahertz modulation-speed using electrically controlled quantum dot microlenses

    NASA Astrophysics Data System (ADS)

    Schlehahn, A.; Schmidt, R.; Hopfmann, C.; Schulze, J.-H.; Strittmatter, A.; Heindel, T.; Gantz, L.; Schmidgall, E. R.; Gershoni, D.; Reitzenstein, S.

    2016-01-01

    We report on the generation of single-photon pulse trains at a repetition rate of up to 1 GHz. We achieve this speed by modulating the external voltage applied on an electrically contacted quantum dot microlens, which is optically excited by a continuous-wave laser. By modulating the photoluminescence of the quantum dot microlens using a square-wave voltage, single-photon emission is triggered with a response time as short as (281 ± 19) ps, being 6 times faster than the radiative lifetime of (1.75 ± 0.02) ns. This large reduction in the characteristic emission time is enabled by a rapid capacitive gating of emission from the quantum dot, which is placed in the intrinsic region of a p-i-n-junction biased below the onset of electroluminescence. Here, since our circuit acts as a rectifying differentiator, the rising edge of the applied voltage pulses triggers the emission of single photons from the optically excited quantum dot. The non-classical nature of the photon pulse train generated at GHz-speed is proven by intensity autocorrelation measurements with g(2)(0) = 0.3 ± 0.1. Our results combine optical excitation with fast electrical gating and thus show promise for the generation of indistinguishable single photons at rates exceeding the limitations set by the intrinsic radiative lifetime.

  3. Ultrafast Room-Temperature Single Photon Emission from Quantum Dots Coupled to Plasmonic Nanocavities.

    PubMed

    Hoang, Thang B; Akselrod, Gleb M; Mikkelsen, Maiken H

    2016-01-13

    Efficient and bright single photon sources at room temperature are critical components for quantum information systems such as quantum key distribution, quantum state teleportation, and quantum computation. However, the intrinsic radiative lifetime of quantum emitters is typically ∼10 ns, which severely limits the maximum single photon emission rate and thus entanglement rates. Here, we demonstrate the regime of ultrafast spontaneous emission (∼10 ps) from a single quantum emitter coupled to a plasmonic nanocavity at room temperature. The nanocavity integrated with a single colloidal semiconductor quantum dot produces a 540-fold decrease in the emission lifetime and a simultaneous 1900-fold increase in the total emission intensity. At the same time, the nanocavity acts as a highly efficient optical antenna directing the emission into a single lobe normal to the surface. This plasmonic platform is a versatile geometry into which a variety of other quantum emitters, such as crystal color centers, can be integrated for directional, room-temperature single photon emission rates exceeding 80 GHz.

  4. Electronic-state-controlled reset operation in quantum dot resonant-tunneling single-photon detectors

    SciTech Connect

    Weng, Q. C.; Zhu, Z. Q.; An, Z. H.; Song, J. D.; Choi, W. J.

    2014-02-03

    The authors present a systematic study of an introduced reset operation on quantum dot (QD) single photon detectors operating at 77 K. The detectors are based on an AlAs/GaAs/AlAs double-barrier resonant tunneling diode with an adjacent layer of self-assembled InAs QDs. Sensitive single-photon detection in high (dI)/(dV) region with suppressed current fluctuations is achieved. The dynamic detection range is extended up to at least 10{sup 4} photons/s for sensitive imaging applications by keeping the device far from saturation by employing an appropriate reset frequency.

  5. Achieving nonreciprocal unidirectional single-photon quantum transport using the photonic Aharonov-Bohm effect.

    PubMed

    Yuan, Luqi; Xu, Shanshan; Fan, Shanhui

    2015-11-15

    We show that nonreciprocal unidirectional single-photon quantum transport can be achieved with the photonic Aharonov-Bohm effect. The system consists of a 1D waveguide coupling to two three-level atoms of the V-type. The two atoms, in addition, are each driven by an external coherent field. We show that the phase of the external coherent field provides a gauge potential for the photon states. With a proper choice of the phase difference between the two coherent fields, the transport of a single photon can exhibit unity contrast in its transmissions for the two propagation directions.

  6. Surface acoustic wave regulated single photon emission from a coupled quantum dot-nanocavity system

    NASA Astrophysics Data System (ADS)

    Weiß, M.; Kapfinger, S.; Reichert, T.; Finley, J. J.; Wixforth, A.; Kaniber, M.; Krenner, H. J.

    2016-07-01

    A coupled quantum dot-nanocavity system in the weak coupling regime of cavity-quantumelectrodynamics is dynamically tuned in and out of resonance by the coherent elastic field of a fSAW ≃ 800 MHz surface acoustic wave. When the system is brought to resonance by the sound wave, light-matter interaction is strongly increased by the Purcell effect. This leads to a precisely timed single photon emission as confirmed by the second order photon correlation function, g(2). All relevant frequencies of our experiment are faithfully identified in the Fourier transform of g(2), demonstrating high fidelity regulation of the stream of single photons emitted by the system.

  7. Nonlinear Quantum Optics in a Waveguide: Distinct Single Photons Strongly Interacting at the Single Atom Level

    SciTech Connect

    Kolchin, Pavel; Oulton, Rupert F.; Zhang Xiang

    2011-03-18

    We propose a waveguide-QED system where two single photons of distinct frequency or polarization interact strongly. The system consists of a single ladder-type three level atom coupled to a waveguide. When both optical transitions are coupled strongly to the waveguide's mode, we show that a control photon tuned to the upper transition induces a {pi} phase shift and tunneling of a probe photon tuned to the otherwise reflective lower transition. Furthermore, the system exhibits single photon scattering by a classical control beam. Waveguide-QED schemes could be an alternative to high quality cavities or dense atomic ensembles in quantum information processing.

  8. Simulating and Optimising Quantum Thermometry Using Single Photons

    PubMed Central

    Tham, W. K.; Ferretti, H.; Sadashivan, A. V.; Steinberg, A. M.

    2016-01-01

    A classical thermometer typically works by exchanging energy with the system being measured until it comes to equilibrium, at which point the readout is related to the final energy state of the thermometer. A recent paper noted that with a quantum thermometer consisting of a single spin/qubit, temperature discrimination is better achieved at finite times rather than once equilibration is essentially complete. Furthermore, preparing a qubit thermometer in a state with quantum coherence instead of an incoherent one improves its sensitivity to temperature differences. Implementing a recent proposal for efficiently emulating an arbitrary quantum channel, we use the quantum polarisation state of individual photons as models of “single-qubit thermometers” which evolve for a certain time in contact with a thermal bath. We investigate the optimal thermometer states for temperature discrimination, and the optimal interaction times, confirming that there is a broad regime where quantum coherence provides a significant improvement. We also discuss the more practical question of thermometers composed of a finite number of spins/qubits (greater than one), and characterize the performance of an adaptive protocol for making optimal use of all the qubits. PMID:27974836

  9. Simulating and Optimising Quantum Thermometry Using Single Photons

    NASA Astrophysics Data System (ADS)

    Tham, W. K.; Ferretti, H.; Sadashivan, A. V.; Steinberg, A. M.

    2016-12-01

    A classical thermometer typically works by exchanging energy with the system being measured until it comes to equilibrium, at which point the readout is related to the final energy state of the thermometer. A recent paper noted that with a quantum thermometer consisting of a single spin/qubit, temperature discrimination is better achieved at finite times rather than once equilibration is essentially complete. Furthermore, preparing a qubit thermometer in a state with quantum coherence instead of an incoherent one improves its sensitivity to temperature differences. Implementing a recent proposal for efficiently emulating an arbitrary quantum channel, we use the quantum polarisation state of individual photons as models of “single-qubit thermometers” which evolve for a certain time in contact with a thermal bath. We investigate the optimal thermometer states for temperature discrimination, and the optimal interaction times, confirming that there is a broad regime where quantum coherence provides a significant improvement. We also discuss the more practical question of thermometers composed of a finite number of spins/qubits (greater than one), and characterize the performance of an adaptive protocol for making optimal use of all the qubits.

  10. Quantum non-Gaussianity of frequency up-converted single photons.

    PubMed

    Baune, Christoph; Schönbeck, Axel; Samblowski, Aiko; Fiurášek, Jaromír; Schnabel, Roman

    2014-09-22

    Nonclassical states of light are an important resource in today's quantum communication and metrology protocols. Quantum up-conversion of nonclassical states is a promising approach to overcome frequency differences between disparate subsystems within a quantum information network. Here, we present the generation of heralded narrowband single photons at 1550 nm via cavity enhanced spontaneous parametric down-conversion (SPDC) and their subsequent up-conversion to 532 nm. Quantum non-Gaussianity (QNG), which is an important feature for applications in quantum information science, was experimentally certified for the first time in frequency up-converted states.

  11. Fault tolerant filtering and fault detection for quantum systems driven by fields in single photon states

    SciTech Connect

    Gao, Qing Dong, Daoyi Petersen, Ian R.; Rabitz, Herschel

    2016-06-15

    The purpose of this paper is to solve the fault tolerant filtering and fault detection problem for a class of open quantum systems driven by a continuous-mode bosonic input field in single photon states when the systems are subject to stochastic faults. Optimal estimates of both the system observables and the fault process are simultaneously calculated and characterized by a set of coupled recursive quantum stochastic differential equations.

  12. Simplified quantum bit commitment using single photon nonlocality

    NASA Astrophysics Data System (ADS)

    He, Guang Ping

    2014-10-01

    We simplified our previously proposed quantum bit commitment (QBC) protocol based on the Mach-Zehnder interferometer, by replacing symmetric beam splitters with asymmetric ones. It eliminates the need for random sending time of the photons; thus, the feasibility and efficiency are both improved. The protocol is immune to the cheating strategy in the Mayers-Lo-Chau no-go theorem of unconditionally secure QBC, because the density matrices of the committed states do not satisfy a crucial condition on which the no-go theorem holds.

  13. p-Shell Rabi-flopping and single photon emission in an InGaAs/GaAs quantum dot

    NASA Astrophysics Data System (ADS)

    Ester, P.; Lackmann, L.; Hübner, M. C.; Michaelis de Vasconcellos, S.; Zrenner, A.; Bichler, M.

    2008-04-01

    Very clean single photon emission from a single InGaAs/GaAs quantum dot is demonstrated by the use of a coherent optical state preparation. We present a concept for single photon emission, which uses p-shell Rabi-flopping followed by a sequence of relaxation and recombination. The proof of the (clean) single photon emission is performed by photon correlation measurements.

  14. A high-temperature single-photon source from nanowire quantum dots.

    PubMed

    Tribu, Adrien; Sallen, Gregory; Aichele, Thomas; André, Régis; Poizat, Jean-Philippe; Bougerol, Catherine; Tatarenko, Serge; Kheng, Kuntheak

    2008-12-01

    We present a high-temperature single-photon source based on a quantum dot inside a nanowire. The nanowires were grown by molecular beam epitaxy in the vapor-liquid-solid growth mode. We utilize a two-step process that allows a thin, defect-free ZnSe nanowire to grow on top of a broader, cone-shaped nanowire. Quantum dots are formed by incorporating a narrow zone of CdSe into the nanowire. We observe intense and highly polarized photoluminescence even from a single emitter. Efficient photon antibunching is observed up to 220 K, while conserving a normalized antibunching dip of at most 36%. This is the highest reported temperature for single-photon emission from a nonblinking quantum-dot source and principally allows compact and cheap operation by using Peltier cooling.

  15. Simple and efficient absorption filter for single photons from a cold atom quantum memory.

    PubMed

    Stack, Daniel T; Lee, Patricia J; Quraishi, Qudsia

    2015-03-09

    The ability to filter unwanted light signals is critical to the operation of quantum memories based on neutral atom ensembles. Here we demonstrate an efficient frequency filter which uses a vapor cell filled with (85)Rb and a buffer gas to attenuate both residual laser light and noise photons by nearly two orders of magnitude with little loss to the single photons associated with our cold (87)Rb quantum memory. This simple, passive filter provides an additional 18 dB attenuation of our pump laser and erroneous spontaneous emissions for every 1 dB loss of the single photon signal. We show that the addition of a frequency filter increases the non-classical correlations and the retrieval efficiency of our quantum memory by ≈ 35%.

  16. Quantum witness of high-speed low-noise single-photon detection.

    PubMed

    Zhao, Lin; Huang, Kun; Liang, Yan; Chen, Jie; Shi, Xueshun; Wu, E; Zeng, Heping

    2015-12-14

    We demonstrate high-speed and low-noise near-infrared single-photon detection by using a capacitance balancing circuit to achieve a high spike noise suppression for an InGaAs/InP avalanche photodiode. The single-photon detector could operate at a tunable gate repetition rate from 10 to 60 MHz. A peak detection efficiency of 34% has been achieved with a dark count rate of 9 × 10⁻³ per gate when the detection window was set to 1 ns. Additionally, quantum detector tomography has also been performed at 60 MHz of repetition rate and for the detection window of 1 ns, enabling to witness the quantum features of the detector with the help of a negative Wigner function. By varying the bias voltage of the detector, we further demonstrated a transition from the full-quantum to semi-classical regime.

  17. Cavity enhanced telecom heralded single photons for spin-wave solid state quantum memories

    NASA Astrophysics Data System (ADS)

    Rieländer, Daniel; Lenhard, Andreas; Mazzera, Margherita; de Riedmatten, Hugues

    2016-12-01

    We report on a source of heralded narrowband (≈ 3 MHz) single photons compatible with solid-state spin-wave quantum memories based on praseodymium doped crystals. Widely non-degenerate narrow-band photon pairs are generated using cavity enhanced down conversion. One photon from the pair is at telecom wavelengths and serves as heralding signal, while the heralded single photon is at 606 nm, resonant with an optical transition of Pr3+:Y2SiO5. The source offers a heralding efficiency of 28% and a generation rate exceeding 2000 pairs mW-1 in a single-mode. The single photon nature of the heralded field is confirmed by a direct antibunching measurement, with a measured antibunching parameter down to 0.010(4). Moreover, we investigate in detail photon cross- and autocorrelation functions proving non-classical correlations between the two photons. The results presented in this paper offer prospects for the demonstration of single photon spin-wave storage in an on-demand solid state quantum memory, heralded by a telecom photon.

  18. Interference with a quantum dot single-photon source and a laser at telecom wavelength

    SciTech Connect

    Felle, M.; Huwer, J. Stevenson, R. M.; Skiba-Szymanska, J.; Ward, M. B.; Shields, A. J.; Farrer, I.; Ritchie, D. A.; Penty, R. V.

    2015-09-28

    The interference of photons emitted by dissimilar sources is an essential requirement for a wide range of photonic quantum information applications. Many of these applications are in quantum communications and need to operate at standard telecommunication wavelengths to minimize the impact of photon losses and be compatible with existing infrastructure. Here, we demonstrate for the first time the quantum interference of telecom-wavelength photons from an InAs/GaAs quantum dot single-photon source and a laser; an important step towards such applications. The results are in good agreement with a theoretical model, indicating a high degree of indistinguishability for the interfering photons.

  19. Single-photon experiments with liquid crystals for quantum science and quantum engineering applications

    NASA Astrophysics Data System (ADS)

    Lukishova, Svetlana G.; Liapis, Andreas C.; Bissell, Luke J.; Gehring, George M.; Winkler, Justin M.; Boyd, Robert W.

    2015-03-01

    We present here our results on using liquid crystals in experiments with nonclassical light sources: (1) single-photon sources exhibiting antibunching (separation of all photons in time), which are key components for secure quantum communication systems, and (2) entangled photon source with photons exhibiting quantum interference in a Hong-Ou- Mandel interferometer. In the first part, cholesteric liquid crystal hosts were used to create definite circular polarization of antibunched photons emitted by nanocrystal quantum dots. If the photon has unknown polarization, filtering it through a polarizer to produce the desired polarization for quantum key distribution with bits based on polarization states of photons will reduce by half the efficiency of a quantum cryptography system. In the first part, we also provide our results on observation of a circular polarized microcavity resonance in nanocrystal quantum dot fluorescence in a 1-D chiral photonic bandgap cholesteric liquid crystal microcavity. In the second part of this paper with indistinguishable, time-entangled photons, we demonstrate our experimental results on simulating quantum-mechanical barrier tunnelling phenomena. A Hong-Ou-Mandel dip (quantum interference effect) is shifted when a phase change was introduced on the way of one of entangled photons in pair (one arm of the interferometer) by inserting in this arm an electrically controlled planar-aligned nematic liquid crystal layer between two prisms in the conditions close to a frustrated total internal reflection. By applying different AC-voltages to the planar-aligned nematic layer and changing its refractive index, we can obtain various conditions for incident photon propagation - from total reflection to total transmission. Measuring changes of tunnelling times of photon through this structure with femtosecond resolution permitted us to answer some unresolved questions in quantum-mechanical barrier tunnelling phenomena.

  20. Linearly polarized single photon antibunching from a site-controlled InGaN quantum dot

    SciTech Connect

    Jemsson, Tomas; Machhadani, Houssaine; Karlsson, K. Fredrik; Hsu, Chih-Wei; Holtz, Per-Olof

    2014-08-25

    We report on the observation of linearly polarized single photon antibunching in the excitonic emission from a site-controlled InGaN quantum dot. The measured second order coherence function exhibits a significant dip at zero time difference, corresponding to g{sub m}{sup 2}(0)=0.90 under continuous laser excitation. This relatively high value of g{sub m}{sup 2}(0) is well understood by a model as the combination of short exciton life time (320 ps), limited experimental timing resolution and the presence of an uncorrelated broadband background emission from the sample. Our result provides the first rigorous evidence of InGaN quantum dot formation on hexagonal GaN pyramids, and it highlights a great potential in these dots as fast polarized single photon emitters if the background emission can be eliminated.

  1. Quantum interference between a single-photon Fock state and a coherent state

    NASA Astrophysics Data System (ADS)

    Windhager, A.; Suda, M.; Pacher, C.; Peev, M.; Poppe, A.

    2011-04-01

    We derive analytical expressions for the single mode quantum field state at the individual output ports of a beam splitter when a single-photon Fock state and a coherent state are incident on the input ports. The output states turn out to be a statistical mixture between a displaced Fock state and a coherent state. Consequently we are able to find an analytical expression for the corresponding Wigner function. Because of the generality of our calculations the obtained results are valid for all passive and lossless optical four port devices. We show further how the results can be adapted to the case of the Mach-Zehnder interferometer. In addition we consider the case for which the single-photon Fock state is replaced with a general input state: a coherent input state displaces each general quantum state at the output port of a beam splitter with the displacement parameter being the amplitude of the coherent state.

  2. Channel analysis for single photon underwater free space quantum key distribution.

    PubMed

    Shi, Peng; Zhao, Shi-Cheng; Gu, Yong-Jian; Li, Wen-Dong

    2015-03-01

    We investigate the optical absorption and scattering properties of underwater media pertinent to our underwater free space quantum key distribution (QKD) channel model. With the vector radiative transfer theory and Monte Carlo method, we obtain the attenuation of photons, the fidelity of the scattered photons, the quantum bit error rate, and the sifted key generation rate of underwater quantum communication. It can be observed from our simulations that the most secure single photon underwater free space QKD is feasible in the clearest ocean water.

  3. Observation of entanglement between a quantum dot spin and a single photon.

    PubMed

    Gao, W B; Fallahi, P; Togan, E; Miguel-Sanchez, J; Imamoglu, A

    2012-11-15

    Entanglement has a central role in fundamental tests of quantum mechanics as well as in the burgeoning field of quantum information processing. Particularly in the context of quantum networks and communication, a main challenge is the efficient generation of entanglement between stationary (spin) and propagating (photon) quantum bits. Here we report the observation of quantum entanglement between a semiconductor quantum dot spin and the colour of a propagating optical photon. The demonstration of entanglement relies on the use of fast, single-photon detection, which allows us to project the photon into a superposition of red and blue frequency components. Our results extend the previous demonstrations of single-spin/single-photon entanglement in trapped ions, neutral atoms and nitrogen-vacancy centres to the domain of artificial atoms in semiconductor nanostructures that allow for on-chip integration of electronic and photonic elements. As a result of its fast optical transitions and favourable selection rules, the scheme we implement could in principle generate nearly deterministic entangled spin-photon pairs at a rate determined ultimately by the high spontaneous emission rate. Our observation constitutes a first step towards implementation of a quantum network with nodes consisting of semiconductor spin quantum bits.

  4. On-chip single photon filtering and multiplexing in hybrid quantum photonic circuits.

    PubMed

    Elshaari, Ali W; Zadeh, Iman Esmaeil; Fognini, Andreas; Reimer, Michael E; Dalacu, Dan; Poole, Philip J; Zwiller, Val; Jöns, Klaus D

    2017-08-30

    Quantum light plays a pivotal role in modern science and future photonic applications. Since the advent of integrated quantum nanophotonics different material platforms based on III-V nanostructures-, colour centers-, and nonlinear waveguides as on-chip light sources have been investigated. Each platform has unique advantages and limitations; however, all implementations face major challenges with filtering of individual quantum states, scalable integration, deterministic multiplexing of selected quantum emitters, and on-chip excitation suppression. Here we overcome all of these challenges with a hybrid and scalable approach, where single III-V quantum emitters are positioned and deterministically integrated in a complementary metal-oxide-semiconductor-compatible photonic circuit. We demonstrate reconfigurable on-chip single-photon filtering and wavelength division multiplexing with a foot print one million times smaller than similar table-top approaches, while offering excitation suppression of more than 95 dB and efficient routing of single photons over a bandwidth of 40 nm. Our work marks an important step to harvest quantum optical technologies' full potential.Combining different integration platforms on the same chip is currently one of the main challenges for quantum technologies. Here, Elshaari et al. show III-V Quantum Dots embedded in nanowires operating in a CMOS compatible circuit, with controlled on-chip filtering and tunable routing.

  5. Single-Event Correlation Analysis of Quantum Key Distribution with Single-Photon Sources

    NASA Astrophysics Data System (ADS)

    Shangli Dong,; Xiaobo Wang,; Guofeng Zhang,; Liantuan Xiao,; Suotang Jia,

    2010-04-01

    Multiple photons exist that allow efficient eavesdropping strategies that threaten the security of quantum key distribution. In this paper, we theoretically discuss the photon correlations between authorized partners in the case of practical single-photon sources including a multiple-photon background. To investigate the feasibility of intercept-resend attacks, the cross correlations and the maximum intercept-resend ratio caused by the background signal are determined using single-event correlation analysis based on single-event detection.

  6. Quantum-Dot Single-Photon Sources for Entanglement Enhanced Interferometry.

    PubMed

    Müller, M; Vural, H; Schneider, C; Rastelli, A; Schmidt, O G; Höfling, S; Michler, P

    2017-06-23

    Multiphoton entangled states such as "N00N states" have attracted a lot of attention because of their possible application in high-precision, quantum enhanced phase determination. So far, N00N states have been generated in spontaneous parametric down-conversion processes and by mixing quantum and classical light on a beam splitter. Here, in contrast, we demonstrate superresolving phase measurements based on two-photon N00N states generated by quantum dot single-photon sources making use of the Hong-Ou-Mandel effect on a beam splitter. By means of pulsed resonance fluorescence of a charged exciton state, we achieve, in postselection, a quantum enhanced improvement of the precision in phase uncertainty, higher than prescribed by the standard quantum limit. An analytical description of the measurement scheme is provided, reflecting requirements, capability, and restraints of single-photon emitters in optical quantum metrology. Our results point toward the realization of a real-world quantum sensor in the near future.

  7. Quantum-Dot Single-Photon Sources for Entanglement Enhanced Interferometry

    NASA Astrophysics Data System (ADS)

    Müller, M.; Vural, H.; Schneider, C.; Rastelli, A.; Schmidt, O. G.; Höfling, S.; Michler, P.

    2017-06-01

    Multiphoton entangled states such as "N00N states" have attracted a lot of attention because of their possible application in high-precision, quantum enhanced phase determination. So far, N00N states have been generated in spontaneous parametric down-conversion processes and by mixing quantum and classical light on a beam splitter. Here, in contrast, we demonstrate superresolving phase measurements based on two-photon N00N states generated by quantum dot single-photon sources making use of the Hong-Ou-Mandel effect on a beam splitter. By means of pulsed resonance fluorescence of a charged exciton state, we achieve, in postselection, a quantum enhanced improvement of the precision in phase uncertainty, higher than prescribed by the standard quantum limit. An analytical description of the measurement scheme is provided, reflecting requirements, capability, and restraints of single-photon emitters in optical quantum metrology. Our results point toward the realization of a real-world quantum sensor in the near future.

  8. On-chip interference of single photons from an embedded quantum dot and an external laser

    SciTech Connect

    Prtljaga, N. Bentham, C.; O'Hara, J.; Royall, B.; Wilson, L. R.; Skolnick, M. S.; Fox, A. M.; Clarke, E.

    2016-06-20

    In this work, we demonstrate the on-chip two-photon interference between single photons emitted by a single self-assembled InGaAs quantum dot and an external laser. The quantum dot is embedded within one arm of an air-clad directional coupler which acts as a beam-splitter for incoming light. Photons originating from an attenuated external laser are coupled to the second arm of the beam-splitter and then combined with the quantum dot photons, giving rise to two-photon quantum interference between dissimilar sources. We verify the occurrence of on-chip Hong-Ou-Mandel interference by cross-correlating the optical signal from the separate output ports of the directional coupler. This experimental approach allows us to use a classical light source (laser) to assess in a single step the overall device performance in the quantum regime and probe quantum dot photon indistinguishability on application realistic time scales.

  9. Quantum Router for Single Photons Carrying Spin and Orbital Angular Momentum.

    PubMed

    Chen, Yuanyuan; Jiang, Dong; Xie, Ling; Chen, Lijun

    2016-06-03

    Quantum router is an essential element in the quantum network. Here, we present a fully quantum router based on interaction free measurement and quantum dots. The signal photonic qubit can be routed to different output ports according to one control electronic qubit. Besides, our scheme is an interferometric method capable of routing single photons carrying either spin angular momentum (SAM) or orbital angular momentum (OAM), or simultaneously carrying SAM and OAM. Then we describe a cascaded multi-level quantum router to construct a one-to-many quantum router. Subsequently we analyze the success probability by using a tunable controlled phase gate. The implementation issues are also discussed to show that this scheme is feasible.

  10. Quantum Router for Single Photons Carrying Spin and Orbital Angular Momentum

    PubMed Central

    Chen, Yuanyuan; Jiang, Dong; Xie, Ling; Chen, Lijun

    2016-01-01

    Quantum router is an essential element in the quantum network. Here, we present a fully quantum router based on interaction free measurement and quantum dots. The signal photonic qubit can be routed to different output ports according to one control electronic qubit. Besides, our scheme is an interferometric method capable of routing single photons carrying either spin angular momentum (SAM) or orbital angular momentum (OAM), or simultaneously carrying SAM and OAM. Then we describe a cascaded multi-level quantum router to construct a one-to-many quantum router. Subsequently we analyze the success probability by using a tunable controlled phase gate. The implementation issues are also discussed to show that this scheme is feasible. PMID:27256772

  11. On-chip interference of single photons from an embedded quantum dot and an external laser

    NASA Astrophysics Data System (ADS)

    Prtljaga, N.; Bentham, C.; O'Hara, J.; Royall, B.; Clarke, E.; Wilson, L. R.; Skolnick, M. S.; Fox, A. M.

    2016-06-01

    In this work, we demonstrate the on-chip two-photon interference between single photons emitted by a single self-assembled InGaAs quantum dot and an external laser. The quantum dot is embedded within one arm of an air-clad directional coupler which acts as a beam-splitter for incoming light. Photons originating from an attenuated external laser are coupled to the second arm of the beam-splitter and then combined with the quantum dot photons, giving rise to two-photon quantum interference between dissimilar sources. We verify the occurrence of on-chip Hong-Ou-Mandel interference by cross-correlating the optical signal from the separate output ports of the directional coupler. This experimental approach allows us to use a classical light source (laser) to assess in a single step the overall device performance in the quantum regime and probe quantum dot photon indistinguishability on application realistic time scales.

  12. Generation of single photons with highly tunable wave shape from a cold atomic quantum memory

    NASA Astrophysics Data System (ADS)

    Heinze, Georg; Farrera, Pau; Albrecht, Boris; de Riedmatten, Hugues; Ho, Melvyn; Chavez, Matias; Teo, Colin; Sangouard, Nicolas

    2016-05-01

    We report on a single photon source with highly tunable photon shape based on a cold ensemble of Rubidium atoms. We follow the DLCZ scheme to implement an emissive quantum memory, which can be operated as a photon pair source with controllable delay. We find that the temporal wave shape of the emitted read photon can be precisely controlled by changing the shape of the driving read pulse. We generate photons with temporal durations varying over three orders of magnitude up to 10 μs without a significant change of the read-out efficiency. We prove the non-classicality of the emitted photons by measuring their antibunching, showing near single photon behavior at low excitation probabilities. We also show that the photons are emitted in a pure state by measuring unconditional autocorrelation functions. Finally, to demonstrate the usability of the source for realistic applications, we create ultra-long single photons with a rising exponential or doubly peaked time-bin wave shape which are important for several quantum information tasks. ICREA-Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain.

  13. Non-Gaussianity of quantum states: An experimental test on single-photon-added coherent states

    SciTech Connect

    Barbieri, Marco; Ferreyrol, Franck; Blandino, Remi; Grangier, Philippe; Tualle-Brouri, Rosa; Spagnolo, Nicolo; Genoni, Marco G.; Paris, Matteo G. A.

    2010-12-15

    Non-Gaussian states and processes are useful resources in quantum information with continuous variables. An experimentally accessible criterion has been proposed to measure the degree of non-Gaussianity of quantum states based on the conditional entropy of the state with a Gaussian reference. Here we adopt such a criterion to characterize an important class of nonclassical states: single-photon-added coherent states. Our studies demonstrate the reliability and sensitivity of this measure and use it to quantify how detrimental is the role of experimental imperfections in our implementation.

  14. Time-reversal-symmetric single-photon wave packets for free-space quantum communication.

    PubMed

    Trautmann, N; Alber, G; Agarwal, G S; Leuchs, G

    2015-05-01

    Readout and retrieval processes are proposed for efficient, high-fidelity quantum state transfer between a matter qubit, encoded in the level structure of a single atom or ion, and a photonic qubit, encoded in a time-reversal-symmetric single-photon wave packet. They are based on controlling spontaneous photon emission and absorption of a matter qubit on demand in free space by stimulated Raman adiabatic passage. As these processes do not involve mode selection by high-finesse cavities or photon transport through optical fibers, they offer interesting perspectives as basic building blocks for free-space quantum-communication protocols.

  15. Surface acoustic wave regulated single photon emission from a coupled quantum dot–nanocavity system

    SciTech Connect

    Weiß, M.; Kapfinger, S.; Wixforth, A.; Krenner, H. J.; Reichert, T.; Finley, J. J.; Kaniber, M.

    2016-07-18

    A coupled quantum dot–nanocavity system in the weak coupling regime of cavity-quantumelectrodynamics is dynamically tuned in and out of resonance by the coherent elastic field of a f{sub SAW} ≃ 800 MHz surface acoustic wave. When the system is brought to resonance by the sound wave, light-matter interaction is strongly increased by the Purcell effect. This leads to a precisely timed single photon emission as confirmed by the second order photon correlation function, g{sup (2)}. All relevant frequencies of our experiment are faithfully identified in the Fourier transform of g{sup (2)}, demonstrating high fidelity regulation of the stream of single photons emitted by the system.

  16. An extremely low-noise heralded single-photon source: A breakthrough for quantum technologies

    NASA Astrophysics Data System (ADS)

    Brida, G.; Degiovanni, I. P.; Genovese, M.; Piacentini, F.; Traina, P.; Della Frera, A.; Tosi, A.; Bahgat Shehata, A.; Scarcella, C.; Gulinatti, A.; Ghioni, M.; Polyakov, S. V.; Migdall, A.; Giudice, A.

    2012-11-01

    Low noise single-photon sources are a critical element for quantum technologies. We present a heralded single-photon source with an extremely low level of residual background photons, by implementing low-jitter detectors and electronics and a fast custom-made pulse generator controlling an optical shutter (a LiNbO3 waveguide optical switch) on the output of the source. This source has a second-order autocorrelation g(2)(0)=0.005(7), and an output noise factor (defined as the ratio of the number of noise photons to total photons at the source output channel) of 0.25(1)%. These are the best performance characteristics reported to date.

  17. High-dimensional quantum key distribution with the entangled single-photon-added coherent state

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Bao, Wan-Su; Bao, Hai-Ze; Zhou, Chun; Jiang, Mu-Sheng; Li, Hong-Wei

    2017-04-01

    High-dimensional quantum key distribution (HD-QKD) can generate more secure bits for one detection event so that it can achieve long distance key distribution with a high secret key capacity. In this Letter, we present a decoy state HD-QKD scheme with the entangled single-photon-added coherent state (ESPACS) source. We present two tight formulas to estimate the single-photon fraction of postselected events and Eve's Holevo information and derive lower bounds on the secret key capacity and the secret key rate of our protocol. We also present finite-key analysis for our protocol by using the Chernoff bound. Our numerical results show that our protocol using one decoy state can perform better than that of previous HD-QKD protocol with the spontaneous parametric down conversion (SPDC) using two decoy states. Moreover, when considering finite resources, the advantage is more obvious.

  18. Near-Transform-Limited Single Photons from an Efficient Solid-State Quantum Emitter

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Duan, Z.-C.; Li, Y.-H.; Chen, Si; Li, J.-P.; He, Y.-M.; Chen, M.-C.; He, Yu; Ding, X.; Peng, Cheng-Zhi; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2016-05-01

    By pulsed s -shell resonant excitation of a single quantum dot-micropillar system, we generate long streams of 1000 near-transform-limited single photons with high mutual indistinguishability. The Hong-Ou-Mandel interference of two photons is measured as a function of their emission time separation varying from 13 ns to 14.7 μ s , where the visibility slightly drops from 95.9(2)% to a plateau of 92.1(5)% through a slow dephasing process occurring at a time scale of 0.7 μ s . A temporal and spectral analysis reveals the pulsed resonance fluorescence single photons are close to the transform limit, which are readily useful for multiphoton entanglement and interferometry experiments.

  19. Near-Transform-Limited Single Photons from an Efficient Solid-State Quantum Emitter.

    PubMed

    Wang, Hui; Duan, Z-C; Li, Y-H; Chen, Si; Li, J-P; He, Y-M; Chen, M-C; He, Yu; Ding, X; Peng, Cheng-Zhi; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2016-05-27

    By pulsed s-shell resonant excitation of a single quantum dot-micropillar system, we generate long streams of 1000 near-transform-limited single photons with high mutual indistinguishability. The Hong-Ou-Mandel interference of two photons is measured as a function of their emission time separation varying from 13 ns to 14.7  μs, where the visibility slightly drops from 95.9(2)% to a plateau of 92.1(5)% through a slow dephasing process occurring at a time scale of 0.7  μs. A temporal and spectral analysis reveals the pulsed resonance fluorescence single photons are close to the transform limit, which are readily useful for multiphoton entanglement and interferometry experiments.

  20. Electrically pumped single-photon emission at room temperature from a single InGaN/GaN quantum dot

    SciTech Connect

    Deshpande, Saniya; Frost, Thomas; Hazari, Arnab; Bhattacharya, Pallab

    2014-10-06

    We demonstrate a semiconductor quantum dot based electrically pumped single-photon source operating at room temperature. Single photons emitted in the red spectral range from single In{sub 0.4}Ga{sub 0.6}N/GaN quantum dots exhibit a second-order correlation value g{sup (2)}(0) of 0.29, and fast recombination lifetime ∼1.3 ±0.3 ns at room temperature. The single-photon source can be driven at an excitation repetition rate of 200 MHz.

  1. Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics.

    PubMed

    Wallraff, A; Schuster, D I; Blais, A; Frunzio, L; Huang, R- S; Majer, J; Kumar, S; Girvin, S M; Schoelkopf, R J

    2004-09-09

    The interaction of matter and light is one of the fundamental processes occurring in nature, and its most elementary form is realized when a single atom interacts with a single photon. Reaching this regime has been a major focus of research in atomic physics and quantum optics for several decades and has generated the field of cavity quantum electrodynamics. Here we perform an experiment in which a superconducting two-level system, playing the role of an artificial atom, is coupled to an on-chip cavity consisting of a superconducting transmission line resonator. We show that the strong coupling regime can be attained in a solid-state system, and we experimentally observe the coherent interaction of a superconducting two-level system with a single microwave photon. The concept of circuit quantum electrodynamics opens many new possibilities for studying the strong interaction of light and matter. This system can also be exploited for quantum information processing and quantum communication and may lead to new approaches for single photon generation and detection.

  2. Single-photon test of hyper-complex quantum theories using a metamaterial

    NASA Astrophysics Data System (ADS)

    Procopio, Lorenzo M.; Rozema, Lee A.; Wong, Zi Jing; Hamel, Deny R.; O'Brien, Kevin; Zhang, Xiang; Dakić, Borivoje; Walther, Philip

    2017-04-01

    In standard quantum mechanics, complex numbers are used to describe the wavefunction. Although this has so far proven sufficient to predict experimental results, there is no theoretical reason to choose them over real numbers or generalizations of complex numbers, that is, hyper-complex numbers. Experiments performed to date have proven that real numbers are insufficient, but the need for hyper-complex numbers remains an open question. Here we experimentally probe hyper-complex quantum theories, studying one of their deviations from complex quantum theory: the non-commutativity of phases. We do so by passing single photons through a Sagnac interferometer containing both a metamaterial with a negative refractive index, and a positive phase shifter. To accomplish this we engineered a fishnet metamaterial to have a negative refractive index at 780 nm. We show that the metamaterial phase commutes with other phases with high precision, allowing us to place limits on a particular prediction of hyper-complex quantum theories.

  3. Femtosecond few-fermion dynamics and deterministic single-photon gain in a quantum dot

    NASA Astrophysics Data System (ADS)

    Sotier, Florian; Thomay, Tim; Hanke, Tobias; Korger, Jan; Mahapatra, Suddhasatta; Frey, Alexander; Brunner, Karl; Bratschitsch, Rudolf; Leitenstorfer, Alfred

    2009-05-01

    The ability to coherently manipulate single electron and photon states is vital for quantum information processing. However, typical quantization and correlation energies restrict processing rates in real implementations owing to the time-energy uncertainty. Here we report optical initialization, manipulation and probing of a single CdSe/ZnSe semiconductor quantum dot on femtosecond timescales, the ultimate limit for clean quantum operations in such `artificial atoms'. Resonant pump-probe measurements on a donor-charged quantum dot reveal that the fundamental exciton absorption is switched off through instantaneous Coulomb renormalization. Optical gain builds up following ultrafast intraband relaxation, with a thermalization rate determined by the electron spin. Operating the system in a nonlinear regime, we demonstrate the ability to change the number of quanta in a femtosecond light pulse by exactly +/-1. This deterministic single-photon amplifier is characterized by a flat gain spectrum.

  4. Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors

    PubMed Central

    Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko

    2015-01-01

    Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks. PMID:26404010

  5. Quantum key distribution over 120 km using ultrahigh purity single-photon source and superconducting single-photon detectors

    NASA Astrophysics Data System (ADS)

    Takemoto, Kazuya; Nambu, Yoshihiro; Miyazawa, Toshiyuki; Sakuma, Yoshiki; Yamamoto, Tsuyoshi; Yorozu, Shinichi; Arakawa, Yasuhiko

    2015-09-01

    Advances in single-photon sources (SPSs) and single-photon detectors (SPDs) promise unique applications in the field of quantum information technology. In this paper, we report long-distance quantum key distribution (QKD) by using state-of-the-art devices: a quantum-dot SPS (QD SPS) emitting a photon in the telecom band of 1.5 μm and a superconducting nanowire SPD (SNSPD). At the distance of 100 km, we obtained the maximal secure key rate of 27.6 bps without using decoy states, which is at least threefold larger than the rate obtained in the previously reported 50-km-long QKD experiment. We also succeeded in transmitting secure keys at the rate of 0.307 bps over 120 km. This is the longest QKD distance yet reported by using known true SPSs. The ultralow multiphoton emissions of our SPS and ultralow dark count of the SNSPD contributed to this result. The experimental results demonstrate the potential applicability of QD SPSs to practical telecom QKD networks.

  6. Narrow-band single-photon emission in the near infrared for quantum key distribution.

    PubMed

    Wu, E; Jacques, Vincent; Zeng, Heping; Grangier, Philippe; Treussart, François; Roch, Jean-François

    2006-02-06

    We present a detailed study of photophysical properties of single color centers in natural diamond samples emitting in the near infrared under optical excitation. Photoluminescence of these single emitters has several striking features, including narrow-band (FWHM 2 nm) fully polarized emission around 780 nm, a short excited-state lifetime of about 2 ns, and perfect photostability at room temperature under our excitation conditions. Development of a triggered single-photon source relying on this single color center is discussed for application to quantum key distribution.

  7. Delayed-choice test of quantum complementarity with interfering single photons.

    PubMed

    Jacques, Vincent; Wu, E; Grosshans, Frédéric; Treussart, François; Grangier, Philippe; Aspect, Alain; Roch, Jean-François

    2008-06-06

    We report an experimental test of quantum complementarity with single-photon pulses sent into a Mach-Zehnder interferometer with an output beam splitter of adjustable reflection coefficient R. In addition, the experiment is realized in Wheeler's delayed-choice regime. Each randomly set value of R allows us to observe interference with visibility V and to obtain incomplete which-path information characterized by the distinguishability parameter D. Measured values of V and D are found to fulfill the complementarity relation V2+D2 < or =1.

  8. Room temperature single-photon detectors for high bit rate quantum key distribution

    SciTech Connect

    Comandar, L. C.; Patel, K. A.; Fröhlich, B. Lucamarini, M.; Sharpe, A. W.; Dynes, J. F.; Yuan, Z. L.; Shields, A. J.; Penty, R. V.

    2014-01-13

    We report room temperature operation of telecom wavelength single-photon detectors for high bit rate quantum key distribution (QKD). Room temperature operation is achieved using InGaAs avalanche photodiodes integrated with electronics based on the self-differencing technique that increases avalanche discrimination sensitivity. Despite using room temperature detectors, we demonstrate QKD with record secure bit rates over a range of fiber lengths (e.g., 1.26 Mbit/s over 50 km). Furthermore, our results indicate that operating the detectors at room temperature increases the secure bit rate for short distances.

  9. Deterministic controlled-NOT gate for single-photon two-qubit quantum logic.

    PubMed

    Fiorentino, Marco; Wong, Franco N C

    2004-08-13

    We demonstrate a robust implementation of a deterministic linear-optical controlled-not gate for single-photon two-qubit quantum logic. A polarization Sagnac interferometer with an embedded 45 degrees -oriented dove prism is used to enable the polarization control qubit to act on the momentum (spatial) target qubit of the same photon. The optical controlled-not gate requires no active stabilization because the two spatial modes share a common path, and it is used to entangle the polarization and momentum qubits.

  10. Multiparty quantum sealed-bid auction using single photons as message carrier

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Jie; Wang, Hai-Bin; Yuan, Gong-Lin; Xu, Yong; Chen, Zhen-Yu; An, Xing-Xing; Ji, Fu-Gao; Gnitou, Gnim Tchalim

    2016-02-01

    In this study, a novel multiparty quantum sealed-bid auction protocol using the single photons as the message carrier of bids is proposed, followed by an example of three-party auction. Compared with those protocols based on the entangled states (GHZ state, EPR pairs, etc.), the present protocol is more economic and feasible within present technology. In order to guarantee the security and the fairness of the auction, the decoy photon checking technique and an improved post-confirmation mechanism with EPR pairs are introduced, respectively.

  11. Generating Entangled Spin States for Quantum Metrology by Single-Photon Detection

    NASA Astrophysics Data System (ADS)

    McConnell, Robert; Zhang, Hao; Cuk, Senka; Hu, Jiazhong; Schleier-Smith, Monika; Vuletic, Vladan

    2014-05-01

    We present a proposal and latest experimental results on a probabilistic but heralded scheme to generate non-Gaussian entangled states of collective spin in large atomic ensembles by means of single-photon detection. One photon announces the preparation of a Dicke state, while two or more photons announce Schrödinger cat states. The entangled states thus produced allow interferometry below the Standard Quantum Limit (SQL). The method produces nearly pure states even for finite photon detection efficiency and weak atom-photon coupling. The entanglement generation can be made quasi-deterministic by means of repeated trial and feedback.

  12. A controllable single photon beam-splitter as a node of a quantum network

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Gautam, Gaurav; Ghosh, Saikat; Kumar, Deepak; Indian Institute of Technology, Kanpur, India Collaboration; Jawaharlal Nehru University, New Delhi, India Collaboration

    2016-05-01

    A theoretical model for a controlled single-photon beam-splitter is proposed and analysed. It consists of two crossed optical-cavities with overlapping waists, dynamically coupled to a single flying atom. The system is shown to route a single photon with near-unity efficiency in an effective ``weak-coupling'' regime. Furthermore, two such nodes, forming a segment of a quantum network, are shown to perform several controlled quantum operations. All one-qubit operations involve a transfer of a photon from one cavity to another in a single node, while two-qubit operations involve transfer from one node to a next one, coupled via an optical fiber. Novel timing protocols for classical optical fields are found to simplify possible experimental realizations along with achievable effective parameter regime. This model can be extended to various other physical systems including gated quantum dots, circuit-QED or opto-mechanical elements. This work is supported by DST-SERB, and DAE, Government of India.

  13. Single-photon continuous-variable quantum key distribution based on the energy-time uncertainty relation

    NASA Astrophysics Data System (ADS)

    Qi, Bing

    2006-09-01

    We propose a new quantum key distribution protocol in which information is encoded on continuous variables of a single photon. In this protocol, Alice randomly encodes her information on either the central frequency of a narrowband single-photon pulse or the time delay of a broadband single-photon pulse, while Bob randomly chooses to do either frequency measurement or time measurement. The security of this protocol rests on the energy-time uncertainty relation, which prevents Eve from simultaneously determining both frequency and time information with arbitrarily high resolution. Since no interferometer is employed in this scheme, it is more robust against various channel noises, such as polarization and phase fluctuations.

  14. Electrically driven single photon emission from a CdSe/ZnSSe single quantum dot at 200 K

    SciTech Connect

    Quitsch, Wolf; Kümmell, Tilmar; Bacher, Gerd; Gust, Arne; Kruse, Carsten; Hommel, Detlef

    2014-09-01

    High temperature operation of an electrically driven single photon emitter based on a single epitaxial quantum dot is reported. CdSe/ZnSSe/MgS quantum dots are embedded into a p-i-n diode architecture providing almost background free excitonic and biexcitonic electroluminescence from individual quantum dots through apertures in the top contacts. Clear antibunching with g{sup 2}(τ = 0) = 0.28 ± 0.20 can be tracked up to T = 200 K, representing the highest temperature for electrically triggered single photon emission from a single quantum dot device.

  15. Picosecond Lifetimes with High Quantum Yields from Single-Photon-Emitting Colloidal Nanostructures at Room Temperature.

    PubMed

    Bidault, Sébastien; Devilez, Alexis; Maillard, Vincent; Lermusiaux, Laurent; Guigner, Jean-Michel; Bonod, Nicolas; Wenger, Jérôme

    2016-04-26

    Minimizing the luminescence lifetime while maintaining a high emission quantum yield is paramount in optimizing the excitation cross-section, radiative decay rate, and brightness of quantum solid-state light sources, particularly at room temperature, where nonradiative processes can dominate. We demonstrate here that DNA-templated 60 and 80 nm diameter gold nanoparticle dimers, featuring one fluorescent molecule, provide single-photon emission with lifetimes that can fall below 10 ps and typical quantum yields in a 45-70% range. Since these colloidal nanostructures are obtained as a purified aqueous suspension, fluorescence spectroscopy can be performed on both fixed and freely diffusing nanostructures to quantitatively estimate the distributions of decay rate and fluorescence intensity enhancements. These data are in excellent agreement with theoretical calculations and demonstrate that millions of bright fluorescent nanostructures, with radiative lifetimes below 100 ps, can be produced in parallel.

  16. Bright single-photon source based on an InAs quantum dot in a silver-embedded nanocone structure

    NASA Astrophysics Data System (ADS)

    Liu, X.; Asano, T.; Odashima, S.; Nakajima, H.; Kumano, H.; Suemune, I.

    2013-04-01

    High photon-extraction efficiency is strongly required for a practical single-photon source. We succeed in fabricating metal (sliver)-embedded nanocone structure incorporating an InAs quantum dot. Efficient photon emission of ˜200 000 photons per second is detected and single-photon emission is demonstrated using autocorrelation measurements. The photon-extraction efficiency as high as 24.6% is obtained from the structure.

  17. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection.

    PubMed

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-03-23

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn "photon-switches" to "OFF" state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished.

  18. Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection

    PubMed Central

    Weng, Qianchun; An, Zhenghua; Zhang, Bo; Chen, Pingping; Chen, Xiaoshuang; Zhu, Ziqiang; Lu, Wei

    2015-01-01

    Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn “photon-switches” to “OFF” state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished. PMID:25797442

  19. Quantum teleportation of multiple degrees of freedom of a single photon.

    PubMed

    Wang, Xi-Lin; Cai, Xin-Dong; Su, Zu-En; Chen, Ming-Cheng; Wu, Dian; Li, Li; Liu, Nai-Le; Lu, Chao-Yang; Pan, Jian-Wei

    2015-02-26

    Quantum teleportation provides a 'disembodied' way to transfer quantum states from one object to another at a distant location, assisted by previously shared entangled states and a classical communication channel. As well as being of fundamental interest, teleportation has been recognized as an important element in long-distance quantum communication, distributed quantum networks and measurement-based quantum computation. There have been numerous demonstrations of teleportation in different physical systems such as photons, atoms, ions, electrons and superconducting circuits. All the previous experiments were limited to the teleportation of one degree of freedom only. However, a single quantum particle can naturally possess various degrees of freedom--internal and external--and with coherent coupling among them. A fundamental open challenge is to teleport multiple degrees of freedom simultaneously, which is necessary to describe a quantum particle fully and, therefore, to teleport it intact. Here we demonstrate quantum teleportation of the composite quantum states of a single photon encoded in both spin and orbital angular momentum. We use photon pairs entangled in both degrees of freedom (that is, hyper-entangled) as the quantum channel for teleportation, and develop a method to project and discriminate hyper-entangled Bell states by exploiting probabilistic quantum non-demolition measurement, which can be extended to more degrees of freedom. We verify the teleportation for both spin-orbit product states and hybrid entangled states, and achieve a teleportation fidelity ranging from 0.57 to 0.68, above the classical limit. Our work is a step towards the teleportation of more complex quantum systems, and demonstrates an increase in our technical control of scalable quantum technologies.

  20. Quantum teleportation of multiple degrees of freedom of a single photon

    NASA Astrophysics Data System (ADS)

    Wang, Xi-Lin; Cai, Xin-Dong; Su, Zu-En; Chen, Ming-Cheng; Wu, Dian; Li, Li; Liu, Nai-Le; Lu, Chao-Yang; Pan, Jian-Wei

    2015-02-01

    Quantum teleportation provides a `disembodied' way to transfer quantum states from one object to another at a distant location, assisted by previously shared entangled states and a classical communication channel. As well as being of fundamental interest, teleportation has been recognized as an important element in long-distance quantum communication, distributed quantum networks and measurement-based quantum computation. There have been numerous demonstrations of teleportation in different physical systems such as photons, atoms, ions, electrons and superconducting circuits. All the previous experiments were limited to the teleportation of one degree of freedom only. However, a single quantum particle can naturally possess various degrees of freedom--internal and external--and with coherent coupling among them. A fundamental open challenge is to teleport multiple degrees of freedom simultaneously, which is necessary to describe a quantum particle fully and, therefore, to teleport it intact. Here we demonstrate quantum teleportation of the composite quantum states of a single photon encoded in both spin and orbital angular momentum. We use photon pairs entangled in both degrees of freedom (that is, hyper-entangled) as the quantum channel for teleportation, and develop a method to project and discriminate hyper-entangled Bell states by exploiting probabilistic quantum non-demolition measurement, which can be extended to more degrees of freedom. We verify the teleportation for both spin-orbit product states and hybrid entangled states, and achieve a teleportation fidelity ranging from 0.57 to 0.68, above the classical limit. Our work is a step towards the teleportation of more complex quantum systems, and demonstrates an increase in our technical control of scalable quantum technologies.

  1. Spatially resolved quantum nano-optics of single photons using an electron microscope.

    PubMed

    Tizei, L H G; Kociak, M

    2013-04-12

    We report on the experimental demonstration of single-photon state generation and characterization in an electron microscope. In this aim we have used low intensity relativistic (energy between 60 and 100 keV) electrons beams focused in a ca. 1 nm probe to excite diamond nanoparticles. This triggered individual neutral nitrogen-vacancy centers to emit photons which could be gathered and sent to a Hanbury Brown-Twiss intensity interferometer. The detection of a dip in the correlation function at small time delays clearly demonstrates antibunching and thus the creation of nonclassical light states. Specifically, we have also demonstrated single-photon states detection. We unveil the mechanism behind quantum states generation in an electron microscope, and show that it clearly makes cathodoluminescence the nanometer scale analog of photoluminescence. By using an extremely small electron probe size and the ability to monitor its position with subnanometer resolution, we also show the possibility of measuring the quantum character of the emitted beam with deep subwavelength resolution.

  2. Observation of the quantum paradox of separation of a single photon from one of its properties

    NASA Astrophysics Data System (ADS)

    Ashby, James M.; Schwarz, Peter D.; Schlosshauer, Maximilian

    2016-07-01

    We report an experimental realization of the quantum paradox of the separation of a single photon from one of its properties (the so-called "quantum Cheshire cat"). We use a modified Sagnac interferometer with displaced paths to produce appropriately pre- and postselected states of heralded single photons. Weak measurements of photon presence and circular polarization are performed in each arm of the interferometer by introducing weak absorbers and small polarization rotations and analyzing changes in the postselected signal. The absorber is found to have an appreciable effect only in one arm of the interferometer, while the polarization rotation significantly affects the signal only when performed in the other arm. We carry out both sequential and simultaneous weak measurements and find good agreement between measured and predicted weak values. In the language of Aharonov et al. and in the sense of the ensemble averages described by weak values, the experiment establishes the separation of a particle from one its properties during the passage through the interferometer.

  3. Direct generation of linearly polarized single photons with a deterministic axis in quantum dots

    NASA Astrophysics Data System (ADS)

    Wang, Tong; Puchtler, Tim J.; Patra, Saroj K.; Zhu, Tongtong; Ali, Muhammad; Badcock, Tom J.; Ding, Tao; Oliver, Rachel A.; Schulz, Stefan; Taylor, Robert A.

    2017-07-01

    We report the direct generation of linearly polarized single photons with a deterministic polarization axis in self-assembled quantum dots (QDs), achieved by the use of non-polar InGaN without complex device geometry engineering. Here, we present a comprehensive investigation of the polarization properties of these QDs and their origin with statistically significant experimental data and rigorous k·p modeling. The experimental study of 180 individual QDs allows us to compute an average polarization degree of 0.90, with a standard deviation of only 0.08. When coupled with theoretical insights, we show that these QDs are highly insensitive to size differences, shape anisotropies, and material content variations. Furthermore, 91% of the studied QDs exhibit a polarization axis along the crystal [1-100] axis, with the other 9% polarized orthogonal to this direction. These features give non-polar InGaN QDs unique advantages in polarization control over other materials, such as conventional polar nitride, InAs, or CdSe QDs. Hence, the ability to generate single photons with polarization control makes non-polar InGaN QDs highly attractive for quantum cryptography protocols.

  4. Room-temperature triggered single photon emission from a III-nitride site-controlled nanowire quantum dot.

    PubMed

    Holmes, Mark J; Choi, Kihyun; Kako, Satoshi; Arita, Munetaka; Arakawa, Yasuhiko

    2014-02-12

    We demonstrate triggered single photon emission at room temperature from a site-controlled III-nitride quantum dot embedded in a nanowire. Moreover, we reveal a remarkable temperature insensitivity of the single photon statistics, and a g((2))[0] value at 300 K of just 0.13. The combination of using high-quality, small, site-controlled quantum dots with a wide-bandgap material system is crucial for providing both sufficient exciton confinement and an emission spectrum with minimal contamination in order to enable room temperature operation. Arrays of such single photon emitters will be useful for room-temperature quantum information processing applications such as on-chip quantum communication.

  5. Efficient recycling strategies for preparing large Fock states from single-photon sources: Applications to quantum metrology

    NASA Astrophysics Data System (ADS)

    Motes, Keith R.; Mann, Ryan L.; Olson, Jonathan P.; Studer, Nicholas M.; Bergeron, E. Annelise; Gilchrist, Alexei; Dowling, Jonathan P.; Berry, Dominic W.; Rohde, Peter P.

    2016-07-01

    Fock states are a fundamental resource for many quantum technologies such as quantum metrology. While much progress has been made in single-photon source technologies, preparing Fock states with a large photon number remains challenging. We present and analyze a bootstrapped approach for nondeterministically preparing large photon-number Fock states by iteratively fusing smaller Fock states on a beamsplitter. We show that by employing state recycling we are able to exponentially improve the preparation rate over conventional schemes, allowing the efficient preparation of large Fock states. The scheme requires single-photon sources, beamsplitters, number-resolved photodetectors, fast-feedforward, and an optical quantum memory.

  6. Two-color single-photon emission from InAs quantum dots: toward logic information management using quantum light.

    PubMed

    Rivas, David; Muñoz-Matutano, Guillermo; Canet-Ferrer, Josep; García-Calzada, Raúl; Trevisi, Giovanna; Seravalli, Luca; Frigeri, Paola; Martínez-Pastor, Juan P

    2014-02-12

    In this work, we propose the use of the Hanbury-Brown and Twiss interferometric technique and a switchable two-color excitation method for evaluating the exciton and noncorrelated electron-hole dynamics associated with single photon emission from indium arsenide (InAs) self-assembled quantum dots (QDs). Using a microstate master equation model we demonstrate that our single QDs are described by nonlinear exciton dynamics. The simultaneous detection of two-color, single photon emission from InAs QDs using these nonlinear dynamics was used to design a NOT AND logic transference function. This computational functionality combines the advantages of working with light/photons as input/output device parameters (all-optical system) and that of a nanodevice (QD size of ∼ 20 nm) while also providing high optical sensitivity (ultralow optical power operational requirements). These system features represent an important and interesting step toward the development of new prototypes for the incoming quantum information technologies.

  7. Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths

    PubMed Central

    Kahl, Oliver; Ferrari, Simone; Kovalyuk, Vadim; Goltsman, Gregory N.; Korneev, Alexander; Pernice, Wolfram H. P.

    2015-01-01

    Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present SNSPDs embedded in nanophotonic integrated circuits which achieve internal quantum efficiencies close to unity at 1550 nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noise-equivalent powers in the 10−19 W/Hz−1/2 range and the timing jitter is as low as 35 ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms. PMID:26061283

  8. Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths.

    PubMed

    Kahl, Oliver; Ferrari, Simone; Kovalyuk, Vadim; Goltsman, Gregory N; Korneev, Alexander; Pernice, Wolfram H P

    2015-06-10

    Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present SNSPDs embedded in nanophotonic integrated circuits which achieve internal quantum efficiencies close to unity at 1550 nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noise-equivalent powers in the 10(-19) W/Hz(-1/2) range and the timing jitter is as low as 35 ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms.

  9. Storage of multiple single-photon pulses emitted from a quantum dot in a solid-state quantum memory

    PubMed Central

    Tang, Jian-Shun; Zhou, Zong-Quan; Wang, Yi-Tao; Li, Yu-Long; Liu, Xiao; Hua, Yi-Lin; Zou, Yang; Wang, Shuang; He, De-Yong; Chen, Geng; Sun, Yong-Nan; Yu, Ying; Li, Mi-Feng; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Li, Chuan-Feng; Guo, Guang-Can

    2015-01-01

    Quantum repeaters are critical components for distributing entanglement over long distances in presence of unavoidable optical losses during transmission. Stimulated by the Duan–Lukin–Cirac–Zoller protocol, many improved quantum repeater protocols based on quantum memories have been proposed, which commonly focus on the entanglement-distribution rate. Among these protocols, the elimination of multiple photons (or multiple photon-pairs) and the use of multimode quantum memory are demonstrated to have the ability to greatly improve the entanglement-distribution rate. Here, we demonstrate the storage of deterministic single photons emitted from a quantum dot in a polarization-maintaining solid-state quantum memory; in addition, multi-temporal-mode memory with 1, 20 and 100 narrow single-photon pulses is also demonstrated. Multi-photons are eliminated, and only one photon at most is contained in each pulse. Moreover, the solid-state properties of both sub-systems make this configuration more stable and easier to be scalable. Our work will be helpful in the construction of efficient quantum repeaters based on all-solid-state devices. PMID:26468996

  10. Storage of multiple single-photon pulses emitted from a quantum dot in a solid-state quantum memory.

    PubMed

    Tang, Jian-Shun; Zhou, Zong-Quan; Wang, Yi-Tao; Li, Yu-Long; Liu, Xiao; Hua, Yi-Lin; Zou, Yang; Wang, Shuang; He, De-Yong; Chen, Geng; Sun, Yong-Nan; Yu, Ying; Li, Mi-Feng; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Li, Chuan-Feng; Guo, Guang-Can

    2015-10-15

    Quantum repeaters are critical components for distributing entanglement over long distances in presence of unavoidable optical losses during transmission. Stimulated by the Duan-Lukin-Cirac-Zoller protocol, many improved quantum repeater protocols based on quantum memories have been proposed, which commonly focus on the entanglement-distribution rate. Among these protocols, the elimination of multiple photons (or multiple photon-pairs) and the use of multimode quantum memory are demonstrated to have the ability to greatly improve the entanglement-distribution rate. Here, we demonstrate the storage of deterministic single photons emitted from a quantum dot in a polarization-maintaining solid-state quantum memory; in addition, multi-temporal-mode memory with 1, 20 and 100 narrow single-photon pulses is also demonstrated. Multi-photons are eliminated, and only one photon at most is contained in each pulse. Moreover, the solid-state properties of both sub-systems make this configuration more stable and easier to be scalable. Our work will be helpful in the construction of efficient quantum repeaters based on all-solid-state devices.

  11. Preparation of a single-photon dark state in a chiral quantum system

    NASA Astrophysics Data System (ADS)

    Zhu, Fengzheng; Zhao, Teng; Zhang, Hebin; Li, Gao-xiang; Ficek, Zbigniew

    2017-02-01

    We examine conditions under which an open quantum system composed of a driven degenerated parametric oscillator cavity and a driven two-level atom coupled to a waveguide could decay to a pure dark state rather than the expected mixed state. The calculations are carried out analytically in a low-dimensional Hilbert space truncated at the double-excitation states of the combined system. The validity of the truncation is confirmed by the exact numerical analysis. It is found that one way to produce the pure state is to chirally couple the cavity and the atom to the waveguide. Another way to produce the pure state is to drive the cavity and the atom with unequal detunings. In both cases, if the driving fields are weak, the produced state is a coherent superposition of only the single-excitation and ground states of the combined system. In addition, we have found a direct correspondence between the generation of the dark state and the photon blockade effect. In other words, the generation of the dark state acts as a blockade to the number of photons so that only a single photon can be present in the cavity. We investigate the normalized second-order correlation function of the cavity field and find that the conditions under which the correlation function vanishes coincide with the conditions for the creation of the pure dark state. This system is, therefore, suggested as an alternative scheme for the generation of single-photon states.

  12. Detection of single photons by a resonant tunneling heterostructure with a quantum dot layer

    SciTech Connect

    Khanin, Yu. N. Vdovin, E. E.

    2010-08-15

    Light absorption by GaAs/AlAs heterostructures with a layer of self-assembled InAs quantum dots (QDs) at resonant tunneling through an energy-selected QD has been investigated. A high sensitivity of the current through this selected tunneling channel to the absorption of single photons with a wavelength {lambda} {<=} 860 nm up to a temperature of 50 K is demonstrated; this sensitivity is caused by the Coulomb effect of the photoexcited holes captured by surrounding QDs on the resonance conditions. It is shown that single-photon absorption can discretely change the current through the system under study by a factor of more than 50. The captured-hole lifetimes have been measured, and a model has been developed to qualitatively describe the experimental data. It is also demonstrated that the InAs monolayer can effectively absorb photons. The properties of the heterostructure studied can be used not only to detect photons but also to design logical valves and optical memory devices.

  13. Enhanced indistinguishability of in-plane single photons by resonance fluorescence on an integrated quantum dot

    NASA Astrophysics Data System (ADS)

    Kalliakos, Sokratis; Brody, Yarden; Bennett, Anthony J.; Ellis, David J. P.; Skiba-Szymanska, Joanna; Farrer, Ian; Griffiths, Jonathan P.; Ritchie, David A.; Shields, Andrew J.

    2016-10-01

    Integrated quantum light sources in photonic circuits are envisaged as the building blocks of future on-chip architectures for quantum logic operations. While semiconductor quantum dots have been proven to be the highly efficient emitters of quantum light, their interaction with the host material induces spectral decoherence, which decreases the indistinguishability of the emitted photons and limits their functionality. Here, we show that the indistinguishability of in-plane photons can be greatly enhanced by performing resonance fluorescence on a quantum dot coupled to a photonic crystal waveguide. We find that the resonant optical excitation of an exciton state induces an increase in the emitted single-photon coherence by a factor of 15. Two-photon interference experiments reveal a visibility of 0.80 ± 0.03, which is in good agreement with our theoretical model. Combined with the high in-plane light-injection efficiency of photonic crystal waveguides, our results pave the way for the use of this system for the on-chip generation and transmission of highly indistinguishable photons.

  14. Single-photon-driven high-order sideband transitions in an ultrastrongly coupled circuit-quantum-electrodynamics system

    NASA Astrophysics Data System (ADS)

    Chen, Zhen; Wang, Yimin; Li, Tiefu; Tian, Lin; Qiu, Yueyin; Inomata, Kunihiro; Yoshihara, Fumiki; Han, Siyuan; Nori, Franco; Tsai, J. S.; You, J. Q.

    2017-07-01

    We report the experimental observation of high-order sideband transitions at the single-photon level in a quantum circuit system of a flux qubit ultrastrongly coupled to a coplanar waveguide resonator. With the coupling strength reaching 10% of the resonator's fundamental frequency, we obtain clear signatures of higher order red-sideband and first-order blue-sideband transitions, which are mainly due to the ultrastrong Rabi coupling. Our observation advances the understanding of ultrastrongly coupled systems and paves the way to study high-order processes in the quantum Rabi model at the single-photon level.

  15. Title: Development of Single photon Quantum Optical Experiments using Type-I and Type-II Spontaneous Parametric Down Conversion

    NASA Astrophysics Data System (ADS)

    Laugharn, Andrew; Maleki, Seyfollah

    We constructed a quantum optical apparatus to control and detect single photons. We generated these photons via Type-I and Type-II spontaneous parametric down conversion by pumping a GaN laser (405nm) incident on a BBO crystal. We detected the two down converted photons (810nm), denoted signal and idler, in coincidence so as to measure and control single photons. We implemented a coincidence counting unite onto an Altera DE2 board and used LabView for data acquisition. We used these photon pairs to demonstrate quantum entanglement and indistinguishability using multiple optical experiments.

  16. Quantum detector tomography of a time-multiplexed superconducting nanowire single-photon detector at telecom wavelengths.

    PubMed

    Natarajan, Chandra M; Zhang, Lijian; Coldenstrodt-Ronge, Hendrik; Donati, Gaia; Dorenbos, Sander N; Zwiller, Val; Walmsley, Ian A; Hadfield, Robert H

    2013-01-14

    Superconducting nanowire single-photon detectors (SNSPDs) are widely used in telecom wavelength optical quantum information science applications. Quantum detector tomography allows the positive-operator-valued measure (POVM) of a single-photon detector to be determined. We use an all-fiber telecom wavelength detector tomography test bed to measure detector characteristics with respect to photon flux and polarization, and hence determine the POVM. We study the SNSPD both as a binary detector and in an 8-bin, fiber based, Time-Multiplexed (TM) configuration at repetition rates up to 4 MHz. The corresponding POVMs provide an accurate picture of the photon number resolving capability of the TM-SNSPD.

  17. Experimental demonstration of optimal universal asymmetric quantum cloning of polarization states of single photons by partial symmetrization

    SciTech Connect

    Cernoch, Antonin; Soubusta, Jan; Celechovska, Lucie; Dusek, Miloslav; Fiurasek, Jaromir

    2009-12-15

    We report on experimental implementation of the optimal universal asymmetric 1->2 quantum cloning machine for qubits encoded into polarization states of single photons. Our linear-optical machine performs asymmetric cloning by partially symmetrizing the input polarization state of signal photon and a blank copy idler photon prepared in a maximally mixed state. We show that the employed method of measurement of mean clone fidelities exhibits strong resilience to imperfect calibration of the relative efficiencies of single-photon detectors used in the experiment. Reliable characterization of the quantum cloner is thus possible even when precise detector calibration is difficult to achieve.

  18. Quantum dots (QDs) immobilization on metal nanowire end-facets for single photon source application

    NASA Astrophysics Data System (ADS)

    Kim, J.; Lee, B. C.; Kang, C.; Lee, S. Y.; Park, J. H.; Shin, H. J.

    2010-02-01

    We introduce a fabrication process to immobilize cadmium selenide (CdSe) Quantum Dots (QDs) on end-facets of metal nanowires, which can be possibly used as a cavity-free unidirectional single photon source with high coupling efficiency due to high Purcell factor. Nanowires were fabricated using E-beam lithography, E-beam evaporation, and lift-off process and finally covered with chemically deposited silicon dioxide (SiO2) layer. End-facets of metal nanowires were defined using wet etching process. QD immobilization was accomplished through surface modifications on both metal and QD surfaces. We immobilized thiol (-SH) functionalized 15 base pair (bp) ssDNA on Au nanowire surface to hybridize with its complimentary amine (- NH3) functionalized 15bp ssDNA and conjugated the amine functionalized 15bp ssDNA with QD. Presenting QD immobilization method showed high selectivity between metal nanowire and SiO2 surfaces.

  19. Low-jitter single flux quantum signal readout from superconducting single photon detector.

    PubMed

    Terai, Hirotaka; Yamashita, Taro; Miki, Shigehito; Makise, Kazumasa; Wang, Zhen

    2012-08-27

    We developed a single-flux-quantum (SFQ) readout technology for superconducting single-photon detectors (SSPDs) to achieve low-jitter signal readout. By optimizing circuit parameters of the SFQ readout circuit, the input current sensitivity was improved below 10 μA, which is smaller than a typical critical current of SSPD. The experiment using a pulse-pattern generator as an input pulse source revealed that the measured jitter of the SFQ readout circuit is well below the system jitter of our measurement setup for the input current level above 15 μA. The measured jitter of the SSPD connected to the SFQ readout circuit was 37 ps full width at half maximum (FWHM) for an SSPD bias current of around 18 μA, which is a significant improvement on 67 ps FWHM jitter observed in conventional readout without an SFQ readout circuit.

  20. Dynamics of InP/(Ga,In)P quantum-dot single-photon emitters

    NASA Astrophysics Data System (ADS)

    Nowak, A. K.; Martín, M. D.; Gallardo, E.; van der Meulen, H. P.; Viña, L.; Calleja, J. M.; Ripalda, J. M.; González, L.; González, Y.

    2011-12-01

    The dynamics of single photon emitters based on InP/(Ga,In)P quantum dots (QDs) has been studied by time-resolved photo luminescence (TRPL) and photon correlation spectroscopy (PCS) up to 50 K. The increase of temperature produces marked effects on the exciton photoluminescence (PL) decay time (τX) and on the anti-bunching time (τR) in the second order photon correlation function. Both times are found to depend on the QD size. A competition of the thermally activated Dark-to-Bright (D→B) exciton transition and the thermal excitation of the carriers to- and from the QD give a good qualitative understanding of the observed results. Resonant excitation at the QD p-states produces a marked decrease of τR together with the appearance of time bunching in a longer time scale.

  1. Quantum frequency translation of single-photon states in a photonic crystal fiber.

    PubMed

    McGuinness, H J; Raymer, M G; McKinstrie, C J; Radic, S

    2010-08-27

    We experimentally demonstrate frequency translation of a nonclassical optical field via four-wave mixing (Bragg-scattering process) in a photonic crystal fiber (PCF). The high nonlinearity and the ability to control dispersion in PCF enable efficient translation between nearby photon channels within the visible to-near-infrared spectral range, useful in quantum networks. Heralded single photons at 683 nm were translated to 659 nm with an efficiency of 28.6±2.2 percent. Second-order correlation measurements on the 683- and 659-nm fields yielded g(683)(2) (0)=0.21±0.02 and g(659)(2) (0)=0.19±0.05, respectively, showing the nonclassical nature of both fields.

  2. Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications

    NASA Astrophysics Data System (ADS)

    Gol'Tsman, G. N.; Korneev, A.; Rubtsova, I.; Milostnaya, I.; Chulkova, G.; Minaeva, O.; Smirnov, K.; Voronov, B.; Sysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, Roman

    2005-03-01

    We present our progress on the research and development of NbN superconducting single-photon detectors (SSPD's) for ultrafast counting of near-infrared photons for secure quantum communications. Our SSPD's operate in the quantum detection mode based on the photon-induced hotspot formation and subsequent development of a transient resistive barrier across an ultrathin and submicron-width superconducting stripe. The devices are fabricated from 4-nm-thick NbN films and kept in the 4.2- to 2-K temperature range. The detector experimental quantum efficiency in the photon-counting mode reaches above 40% for the visible light and up to 30% in the 1.3- to 1.55-μm wavelength range with dark counts below 0.01 per second. The experimental real-time counting rate is above 2 GHz and is limited by our readout electronics. The SSPD's timing jitter is below 18 ps, and the best-measured value of the noise-equivalent power (NEP) is 5 × 10-21 W/Hz1/2 at 1.3 μm. In terms of quantum efficiency, timing jitter, and maximum counting rate, our NbN SSPD's significantly outperform semiconductor avalanche photodiodes and photomultipliers in the 1.3- to 1.55-μm range.

  3. Single-photon test of hyper-complex quantum theories using a metamaterial

    PubMed Central

    Procopio, Lorenzo M.; Rozema, Lee A.; Wong, Zi Jing; Hamel, Deny R.; O'Brien, Kevin; Zhang, Xiang; Dakić, Borivoje; Walther, Philip

    2017-01-01

    In standard quantum mechanics, complex numbers are used to describe the wavefunction. Although this has so far proven sufficient to predict experimental results, there is no theoretical reason to choose them over real numbers or generalizations of complex numbers, that is, hyper-complex numbers. Experiments performed to date have proven that real numbers are insufficient, but the need for hyper-complex numbers remains an open question. Here we experimentally probe hyper-complex quantum theories, studying one of their deviations from complex quantum theory: the non-commutativity of phases. We do so by passing single photons through a Sagnac interferometer containing both a metamaterial with a negative refractive index, and a positive phase shifter. To accomplish this we engineered a fishnet metamaterial to have a negative refractive index at 780 nm. We show that the metamaterial phase commutes with other phases with high precision, allowing us to place limits on a particular prediction of hyper-complex quantum theories. PMID:28429711

  4. Single-photon quantum nonlocality: Violation of the Clauser-Horne-Shimony-Holt inequality using feasible measurement setups

    NASA Astrophysics Data System (ADS)

    Lee, Su-Yong; Park, Jiyong; Kim, Jaewan; Noh, Changsuk

    2017-01-01

    We investigate quantum nonlocality of a single-photon entangled state under feasible measurement techniques consisting of on-off and homodyne detections along with unitary operations of displacement and squeezing. We test for a potential violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality, in which each of the bipartite party has a freedom to choose between two measurement settings, with each measurement yielding a binary outcome. We find that single-photon quantum nonlocality can be detected when two or less of the four total measurements are carried out by homodyne detection. The largest violation of the CHSH inequality is obtained when all four measurements are squeezed-and-displaced on-off detections. We test the robustness of violations against imperfections in on-off detectors and single-photon sources, finding that the squeezed-and-displaced measurement schemes perform better than the displacement-only measurement schemes.

  5. Frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory.

    PubMed

    Fisher, Kent A G; England, Duncan G; MacLean, Jean-Philippe W; Bustard, Philip J; Resch, Kevin J; Sussman, Benjamin J

    2016-04-05

    The spectral manipulation of photons is essential for linking components in a quantum network. Large frequency shifts are needed for conversion between optical and telecommunication frequencies, while smaller shifts are useful for frequency-multiplexing quantum systems, in the same way that wavelength division multiplexing is used in classical communications. Here we demonstrate frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory. Heralded 723.5 nm photons, with 4.1 nm bandwidth, are stored as optical phonons in the diamond via a Raman transition. Upon retrieval from the diamond memory, the spectral shape of the photons is determined by a tunable read pulse through the reverse Raman transition. We report central frequency tunability over 4.2 times the input bandwidth, and bandwidth modulation between 0.5 and 1.9 times the input bandwidth. Our results demonstrate the potential for diamond, and Raman memories in general, as an integrated platform for photon storage and spectral conversion.

  6. Frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory

    PubMed Central

    Fisher, Kent A. G.; England, Duncan G.; MacLean, Jean-Philippe W.; Bustard, Philip J.; Resch, Kevin J.; Sussman, Benjamin J.

    2016-01-01

    The spectral manipulation of photons is essential for linking components in a quantum network. Large frequency shifts are needed for conversion between optical and telecommunication frequencies, while smaller shifts are useful for frequency-multiplexing quantum systems, in the same way that wavelength division multiplexing is used in classical communications. Here we demonstrate frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory. Heralded 723.5 nm photons, with 4.1 nm bandwidth, are stored as optical phonons in the diamond via a Raman transition. Upon retrieval from the diamond memory, the spectral shape of the photons is determined by a tunable read pulse through the reverse Raman transition. We report central frequency tunability over 4.2 times the input bandwidth, and bandwidth modulation between 0.5 and 1.9 times the input bandwidth. Our results demonstrate the potential for diamond, and Raman memories in general, as an integrated platform for photon storage and spectral conversion. PMID:27045988

  7. Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications

    NASA Astrophysics Data System (ADS)

    Verevkin, A.; Pearlman, A.; Słysz, W.; Zhang, J.; Currie, M.; Korneev, A.; Chulkova, G.; Okunev, O.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol'Tsman, G. N.; Sobolewski, Roman

    2004-09-01

    The paper reports progress on the design and development of niobium-nitride, superconducting single-photon detectors (SSPDs) for ultrafast counting of near-infrared photons for secure quantum communications. The SSPDs operate in the quantum detection mode, based on photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-width superconducting stripe. The devices are fabricated from 3.5 nm thick NbN films and kept at cryogenic (liquid helium) temperatures inside a cryostat. The detector experimental quantum efficiency in the photon-counting mode reaches above 20% in the visible radiation range and up to 10% at the 1.3-1.55 µm infrared range. The dark counts are below 0.01 per second. The measured real-time counting rate is above 2 GHz and is limited by readout electronics (the intrinsic response time is below 30 ps). The SSPD jitter is below 18 ps, and the best-measured value of the noise-equivalent power (NEP) is 2 × 10-18 W/Hz1/2 at 1.3 µm. In terms of photon-counting efficiency and speed, these NbN SSPDs significantly outperform semiconductor avalanche photodiodes and photomultipliers.

  8. On-chip time resolved detection of quantum dot emission using integrated superconducting single photon detectors

    PubMed Central

    Reithmaier, G.; Lichtmannecker, S.; Reichert, T.; Hasch, P.; Müller, K.; Bichler, M.; Gross, R.; Finley, J. J.

    2013-01-01

    We report the routing of quantum light emitted by self-assembled InGaAs quantum dots (QDs) into the optical modes of a GaAs ridge waveguide and its efficient detection on-chip via evanescent coupling to NbN superconducting nanowire single photon detectors (SSPDs). The waveguide coupled SSPDs primarily detect QD luminescence, with scattered photons from the excitation laser onto the proximal detector being negligible by comparison. The SSPD detection efficiency from the evanescently coupled waveguide modes is shown to be two orders of magnitude larger when compared with operation under normal incidence illumination, due to the much longer optical interaction length. Furthermore, in-situ time resolved measurements performed using the integrated detector show an average QD spontaneous emission lifetime of 0.95 ns, measured with a timing jitter of only 72 ps. The performance metrics of the SSPD integrated directly onto GaAs nano-photonic hardware confirms the strong potential for on-chip few-photon quantum optics using such semiconductor-superconductor hybrid systems. PMID:23712624

  9. Distributing entanglement and single photons through an intra-city, free-space quantum channel.

    PubMed

    Resch, K; Lindenthal, M; Blauensteiner, B; Böhm, H; Fedrizzi, A; Kurtsiefer, C; Poppe, A; Schmitt-Manderbach, T; Taraba, M; Ursin, R; Walther, P; Weier, H; Weinfurter, H; Zeilinger, A

    2005-01-10

    We have distributed entangled photons directly through the atmosphere to a receiver station 7.8 km away over the city of Vienna, Austria at night. Detection of one photon from our entangled pairs constitutes a triggered single photon source from the sender. With no direct time-stable connection, the two stations found coincidence counts in the detection events by calculating the cross-correlation of locally-recorded time stamps shared over a public internet channel. For this experiment, our quantum channel was maintained for a total of 40 minutes during which time a coincidence lock found approximately 60000 coincident detection events. The polarization correlations in those events yielded a Bell parameter, S=2.27+/-0.019, which violates the CHSH-Bell inequality by 14 standard deviations. This result is promising for entanglement-based freespace quantum communication in high-density urban areas. It is also encouraging for optical quantum communication between ground stations and satellites since the length of our free-space link exceeds the atmospheric equivalent.

  10. On-chip time resolved detection of quantum dot emission using integrated superconducting single photon detectors.

    PubMed

    Reithmaier, G; Lichtmannecker, S; Reichert, T; Hasch, P; Müller, K; Bichler, M; Gross, R; Finley, J J

    2013-01-01

    We report the routing of quantum light emitted by self-assembled InGaAs quantum dots (QDs) into the optical modes of a GaAs ridge waveguide and its efficient detection on-chip via evanescent coupling to NbN superconducting nanowire single photon detectors (SSPDs). The waveguide coupled SSPDs primarily detect QD luminescence, with scattered photons from the excitation laser onto the proximal detector being negligible by comparison. The SSPD detection efficiency from the evanescently coupled waveguide modes is shown to be two orders of magnitude larger when compared with operation under normal incidence illumination, due to the much longer optical interaction length. Furthermore, in-situ time resolved measurements performed using the integrated detector show an average QD spontaneous emission lifetime of 0.95 ns, measured with a timing jitter of only 72 ps. The performance metrics of the SSPD integrated directly onto GaAs nano-photonic hardware confirms the strong potential for on-chip few-photon quantum optics using such semiconductor-superconductor hybrid systems.

  11. Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission

    PubMed Central

    Sapienza, Luca; Davanço, Marcelo; Badolato, Antonio; Srinivasan, Kartik

    2015-01-01

    Self-assembled, epitaxially grown InAs/GaAs quantum dots (QDs) are promising semiconductor quantum emitters that can be integrated on a chip for a variety of photonic quantum information science applications. However, self-assembled growth results in an essentially random in-plane spatial distribution of QDs, presenting a challenge in creating devices that exploit the strong interaction of single QDs with highly confined optical modes. Here, we present a photoluminescence imaging approach for locating single QDs with respect to alignment features with an average position uncertainty <30 nm (<10 nm when using a solid-immersion lens), which represents an enabling technology for the creation of optimized single QD devices. To that end, we create QD single-photon sources, based on a circular Bragg grating geometry, that simultaneously exhibit high collection efficiency (48%±5% into a 0.4 numerical aperture lens, close to the theoretically predicted value of 50%), low multiphoton probability (g(2)(0) <1%), and a significant Purcell enhancement factor (≈3). PMID:26211442

  12. High-efficiency WSi superconducting nanowire single-photon detectors for quantum state engineering in the near infrared.

    PubMed

    Le Jeannic, Hanna; Verma, Varun B; Cavaillès, Adrien; Marsili, Francesco; Shaw, Matthew D; Huang, Kun; Morin, Olivier; Nam, Sae Woo; Laurat, Julien

    2016-11-15

    We report on high-efficiency superconducting nanowire single-photon detectors based on amorphous tungsten silicide and optimized at 1064 nm. At an operating temperature of 1.8 K, we demonstrated a 93% system detection efficiency at this wavelength with a dark noise of a few counts per second. Combined with cavity-enhanced spontaneous parametric downconversion, this fiber-coupled detector enabled us to generate narrowband single photons with a heralding efficiency greater than 90% and a high spectral brightness of 0.6×104 photons/(s·mW·MHz). Beyond single-photon generation at large rate, such high-efficiency detectors open the path to efficient multiple-photon heralding and complex quantum state engineering.

  13. High-efficiency WSi superconducting nanowire single-photon detectors for quantum state engineering in the near infrared

    NASA Astrophysics Data System (ADS)

    Le Jeannic, Hanna; Verma, Varun B.; Cavaillès, Adrien; Marsili, Francesco; Shaw, Matthew D.; Huang, Kun; Morin, Olivier; Nam, Sae Woo; Laurat, Julien

    2016-11-01

    We report on high-efficiency superconducting nanowire single-photon detectors based on amorphous WSi and optimized at 1064 nm. At an operating temperature of 1.8 K, we demonstrated a 93% system detection efficiency at this wavelength with a dark noise of a few counts per second. Combined with cavity-enhanced spontaneous parametric down-conversion, this fiber-coupled detector enabled us to generate narrowband single photons with a heralding efficiency greater than 90% and a high spectral brightness of $0.6\\times10^4$ photons/(s$\\cdot$mW$\\cdot$MHz). Beyond single-photon generation at large rate, such high-efficiency detectors open the path to efficient multiple-photon heralding and complex quantum state engineering.

  14. Quantum switch in coupled-resonator array: Controlling single-photon transport by the state of two-level system

    NASA Astrophysics Data System (ADS)

    Qin, Xiao-Ke

    2016-12-01

    We present the model that two-level system (TLS) nonlocally interacts with one-dimensional coupled-resonator array (CRA). The coherent transport of single-photon inside CRA is well controlled by the state of TLS, which functions as quantum switch. Spin up and spin down correspond to switch on and switch off respectively, or vice versa, which originate from the constructive interference and the destructive interference of two coupling paths. We improve the fidelity of quantum switch by preadjusting the frequency of resonators which couple to TLS. Quantum switch realizes quantum beam splitter when TLS is in the superposition state. The single-photon wave packet would entangle with qubit and propagate to the remote resonators.

  15. Deterministic and robust generation of single photons from a single quantum dot with 99.5% indistinguishability using adiabatic rapid passage.

    PubMed

    Wei, Yu-Jia; He, Yu-Ming; Chen, Ming-Cheng; Hu, Yi-Nan; He, Yu; Wu, Dian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2014-11-12

    Single photons are attractive candidates of quantum bits (qubits) for quantum computation and are the best messengers in quantum networks. Future scalable, fault-tolerant photonic quantum technologies demand both stringently high levels of photon indistinguishability and generation efficiency. Here, we demonstrate deterministic and robust generation of pulsed resonance fluorescence single photons from a single semiconductor quantum dot using adiabatic rapid passage, a method robust against fluctuation of driving pulse area and dipole moments of solid-state emitters. The emitted photons are background-free, have a vanishing two-photon emission probability of 0.3% and a raw (corrected) two-photon Hong-Ou-Mandel interference visibility of 97.9% (99.5%), reaching a precision that places single photons at the threshold for fault-tolerant surface-code quantum computing. This single-photon source can be readily scaled up to multiphoton entanglement and used for quantum metrology, boson sampling, and linear optical quantum computing.

  16. Single Quantum Dot with Microlens and 3D-Printed Micro-objective as Integrated Bright Single-Photon Source.

    PubMed

    Fischbach, Sarah; Schlehahn, Alexander; Thoma, Alexander; Srocka, Nicole; Gissibl, Timo; Ristok, Simon; Thiele, Simon; Kaganskiy, Arsenty; Strittmatter, André; Heindel, Tobias; Rodt, Sven; Herkommer, Alois; Giessen, Harald; Reitzenstein, Stephan

    2017-06-21

    Integrated single-photon sources with high photon-extraction efficiency are key building blocks for applications in the field of quantum communications. We report on a bright single-photon source realized by on-chip integration of a deterministic quantum dot microlens with a 3D-printed multilens micro-objective. The device concept benefits from a sophisticated combination of in situ 3D electron-beam lithography to realize the quantum dot microlens and 3D femtosecond direct laser writing for creation of the micro-objective. In this way, we obtain a high-quality quantum device with broadband photon-extraction efficiency of (40 ± 4)% and high suppression of multiphoton emission events with g((2))(τ = 0) < 0.02. Our results highlight the opportunities that arise from tailoring the optical properties of quantum emitters using integrated optics with high potential for the further development of plug-and-play fiber-coupled single-photon sources.

  17. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

    PubMed Central

    Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

    2015-01-01

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances. PMID:26597223

  18. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits.

    PubMed

    Yu, Leo; Natarajan, Chandra M; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S; Tanner, Michael G; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H; Fejer, Martin M; Yamamoto, Yoshihisa

    2015-11-24

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

  19. Single Quantum Dot with Microlens and 3D-Printed Micro-objective as Integrated Bright Single-Photon Source

    PubMed Central

    2017-01-01

    Integrated single-photon sources with high photon-extraction efficiency are key building blocks for applications in the field of quantum communications. We report on a bright single-photon source realized by on-chip integration of a deterministic quantum dot microlens with a 3D-printed multilens micro-objective. The device concept benefits from a sophisticated combination of in situ 3D electron-beam lithography to realize the quantum dot microlens and 3D femtosecond direct laser writing for creation of the micro-objective. In this way, we obtain a high-quality quantum device with broadband photon-extraction efficiency of (40 ± 4)% and high suppression of multiphoton emission events with g(2)(τ = 0) < 0.02. Our results highlight the opportunities that arise from tailoring the optical properties of quantum emitters using integrated optics with high potential for the further development of plug-and-play fiber-coupled single-photon sources. PMID:28670600

  20. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

    NASA Astrophysics Data System (ADS)

    Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

    2015-11-01

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

  1. Absorption spectroscopy at the ultimate quantum limit from single-photon states

    NASA Astrophysics Data System (ADS)

    Whittaker, R.; Erven, C.; Neville, A.; Berry, M.; O’Brien, J. L.; Cable, H.; Matthews, J. C. F.

    2017-02-01

    Absorption spectroscopy is routinely used to characterise chemical and biological samples. For the state-of-the-art in laser absorption spectroscopy, precision is theoretically limited by shot-noise due to the fundamental Poisson-distribution of photon number in laser radiation. In practice, the shot-noise limit can only be achieved when all other sources of noise are eliminated. Here, we use wavelength-correlated and tuneable photon pairs to demonstrate how absorption spectroscopy can be performed with precision beyond the shot-noise limit and near the ultimate quantum limit by using the optimal probe for absorption measurement—single photons. We present a practically realisable scheme, which we characterise both the precision and accuracy of by measuring the response of a control feature. We demonstrate that the technique can successfully probe liquid samples and using two spectrally similar types of haemoglobin we show that obtaining a given precision in resolution requires fewer heralded single probe photons compared to using an idealised laser.

  2. Quantum key agreement protocols with single photon in both polarization and spatial-mode degrees of freedom

    NASA Astrophysics Data System (ADS)

    Wang, Lili; Ma, Wenping

    2017-05-01

    In this paper, we propose a three-party and a multi-party quantum key agreement protocols with single photons in both polarization and spatial-mode degrees of freedom. Based on the defined collective unitary operations, the participants can agree on a secure shared key through encoding their sub-secret keys on the particles. Moreover, the security of our protocols is discussed comprehensively. It is showed that the presented protocols can defend both the outside attacks and participant attacks. The efficiency analysis also shows that our two protocols can achieve high qubit efficiency. Besides, our protocols are feasible since the preparation and the measurement of single-photon state in both polarization and spatial-mode degrees of freedom are available with current quantum techniques.

  3. Teleportation of electronic many-qubit states encoded in the electron spin of quantum dots via single photons.

    PubMed

    Leuenberger, Michael N; Flatté, Michael E; Awschalom, D D

    2005-03-18

    We propose a teleportation scheme that relies only on single-photon measurements and Faraday rotation, for teleportation of many-qubit entangled states stored in the electron spins of a quantum dot system. The interaction between a photon and the two electron spins, via Faraday rotation in microcavities, establishes Greenberger-Horne-Zeilinger entanglement in the spin-photon-spin system. The appropriate single-qubit measurements, and the communication of two classical bits, produce teleportation. This scheme provides the essential link between spintronic and photonic quantum information devices by permitting quantum information to be exchanged between them.

  4. Observation of quantum interference between a single-photon state and a thermal state generated in optical fibers.

    PubMed

    Li, Xiaoying; Yang, Lei; Cui, Liang; Ou, Zhe Yu; Yu, Daoyin

    2008-08-18

    We experimentally demonstrate a Hong-Ou-Mandel type of two-photon interference effect with a heralded single-photon state and a thermal state. The light sources in the 1550 nm telecom band are generated from two independent dispersion-shifted fibers via four-wave mixing process. The observed visibility is (82+/- 11)%. This type of interference between independent sources is crucial in quantum information process with independent qubits.

  5. Nearly Blinking-Free, High-Purity Single-Photon Emission by Colloidal InP/ZnSe Quantum Dots.

    PubMed

    Chandrasekaran, Vigneshwaran; Tessier, Mickaël D; Dupont, Dorian; Geiregat, Pieter; Hens, Zeger; Brainis, Edouard

    2017-10-11

    Colloidal core/shell InP/ZnSe quantum dots (QDs), recently produced using an improved synthesis method, have a great potential in life-science applications as well as in integrated quantum photonics and quantum information processing as single-photon emitters. Single-particle spectroscopy of 10 nm QDs with 3.2 nm cores reveals strong photon antibunching attributed to fast (70 ps) Auger recombination of multiple excitons. The QDs exhibit very good photostability under strong optical excitation. We demonstrate that the antibunching is preserved when the QDs are excited above the saturation intensity of the fundamental-exciton transition. This result paves the way toward their usage as high-purity on-demand single-photon emitters at room temperature. Unconventionally, despite the strong Auger blockade mechanism, InP/ZnSe QDs also display very little luminescence intermittency ("blinking"), with a simple on/off blinking pattern. The analysis of single-particle luminescence statistics places these InP/ZnSe QDs in the class of nearly blinking-free QDs, with emission stability comparable to state-of-the-art thick-shell and alloyed-interface CdSe/CdS, but with improved single-photon purity.

  6. Realizing the measure-device-independent quantum-key-distribution with passive heralded-single photon sources

    PubMed Central

    Wang, Qin; Zhou, Xing-Yu; Guo, Guang-Can

    2016-01-01

    In this paper, we put forward a new approach towards realizing measurement-device-independent quantum key distribution with passive heralded single-photon sources. In this approach, both Alice and Bob prepare the parametric down-conversion source, where the heralding photons are labeled according to different types of clicks from the local detectors, and the heralded ones can correspondingly be marked with different tags at the receiver’s side. Then one can obtain four sets of data through using only one-intensity of pump light by observing different kinds of clicks of local detectors. By employing the newest formulae to do parameter estimation, we could achieve very precise prediction for the two-single-photon pulse contribution. Furthermore, by carrying out corresponding numerical simulations, we compare the new method with other practical schemes of measurement-device-independent quantum key distribution. We demonstrate that our new proposed passive scheme can exhibit remarkable improvement over the conventional three-intensity decoy-state measurement-device-independent quantum key distribution with either heralded single-photon sources or weak coherent sources. Besides, it does not need intensity modulation and can thus diminish source-error defects existing in several other active decoy-state methods. Therefore, if taking intensity modulating errors into account, our new method will show even more brilliant performance. PMID:27759085

  7. Realizing the measure-device-independent quantum-key-distribution with passive heralded-single photon sources

    NASA Astrophysics Data System (ADS)

    Wang, Qin; Zhou, Xing-Yu; Guo, Guang-Can

    2016-10-01

    In this paper, we put forward a new approach towards realizing measurement-device-independent quantum key distribution with passive heralded single-photon sources. In this approach, both Alice and Bob prepare the parametric down-conversion source, where the heralding photons are labeled according to different types of clicks from the local detectors, and the heralded ones can correspondingly be marked with different tags at the receiver’s side. Then one can obtain four sets of data through using only one-intensity of pump light by observing different kinds of clicks of local detectors. By employing the newest formulae to do parameter estimation, we could achieve very precise prediction for the two-single-photon pulse contribution. Furthermore, by carrying out corresponding numerical simulations, we compare the new method with other practical schemes of measurement-device-independent quantum key distribution. We demonstrate that our new proposed passive scheme can exhibit remarkable improvement over the conventional three-intensity decoy-state measurement-device-independent quantum key distribution with either heralded single-photon sources or weak coherent sources. Besides, it does not need intensity modulation and can thus diminish source-error defects existing in several other active decoy-state methods. Therefore, if taking intensity modulating errors into account, our new method will show even more brilliant performance.

  8. Goos-Hänchen shifts in a four-level quantum system near plasmonic nanostructure

    NASA Astrophysics Data System (ADS)

    Jabbari, M.

    2016-05-01

    Goos-Hänchen (GH) shifts of the reflected and transmitted probe beams through a cavity with a four-level quantum system and plasmonic nanostructure is investigated. It is realized that for different values of distance between plasmonic nanostructure and quantum system, the negative and positive GH shifts of the reflected and transmitted probe beams can be controlled. In addition, it is found that the relative phase of applied fields in the presence of plasmonic nanostructure can be used as an important parameter for controlling the GH shifts in reflected and transmitted light through the cavity. Moreover, the distance effect between four-level quantum system and plasmonic nanostructure has also been discussed on lateral shifts of reflected and transmitted light.

  9. High quantum efficiency and low dark count rate in multi-layer superconducting nanowire single-photon detectors

    SciTech Connect

    Jafari Salim, A. Eftekharian, A.; Hamed Majedi, A.

    2014-02-07

    In this paper, we theoretically show that a multi-layer superconducting nanowire single-photon detector (SNSPD) is capable of approaching characteristics of an ideal SNSPD in terms of the quantum efficiency, dark count, and band-width. A multi-layer structure improves the performance in two ways. First, the potential barrier for thermally activated vortex crossing, which is the major source of dark counts and the reduction of the critical current in SNSPDs is elevated. In a multi-layer SNSPD, a vortex is made of 2D-pancake vortices that form a stack. It will be shown that the stack of pancake vortices effectively experiences a larger potential barrier compared to a vortex in a single-layer SNSPD. This leads to an increase in the experimental critical current as well as significant decrease in the dark count rate. In consequence, an increase in the quantum efficiency for photons of the same energy or an increase in the sensitivity to photons of lower energy is achieved. Second, a multi-layer structure improves the efficiency of single-photon absorption by increasing the effective optical thickness without compromising the single-photon sensitivity.

  10. A quantum dot single-photon source with on-the-fly all-optical polarization control and timed emission

    PubMed Central

    Heinze, Dirk; Breddermann, Dominik; Zrenner, Artur; Schumacher, Stefan

    2015-01-01

    Sources of single photons are key elements for applications in quantum information science. Among the different sources available, semiconductor quantum dots excel with their integrability in semiconductor on-chip solutions and the potential that photon emission can be triggered on demand. Usually, the photon is emitted from a single-exciton ground state. Polarization of the photon and time of emission are either probabilistic or pre-determined by electronic properties of the system. Here, we study the direct two-photon emission from the biexciton. The two-photon emission is enabled by a laser pulse driving the system into a virtual state inside the band gap. From this intermediate state, the single photon of interest is then spontaneously emitted. We show that emission through this higher-order transition provides a versatile approach to generate a single photon. Through the driving laser pulse, polarization state, frequency and emission time of the photon can be controlled on-the-fly. PMID:26436776

  11. Storage and retrieval of THz-bandwidth single photons using a room-temperature diamond quantum memory.

    PubMed

    England, Duncan G; Fisher, Kent A G; MacLean, Jean-Philippe W; Bustard, Philip J; Lausten, Rune; Resch, Kevin J; Sussman, Benjamin J

    2015-02-06

    We report the storage and retrieval of single photons, via a quantum memory, in the optical phonons of a room-temperature bulk diamond. The THz-bandwidth heralded photons are generated by spontaneous parametric down-conversion and mapped to phonons via a Raman transition, stored for a variable delay, and released on demand. The second-order correlation of the memory output is g((2))(0)=0.65±0.07, demonstrating a preservation of nonclassical photon statistics throughout storage and retrieval. The memory is low noise, high speed and broadly tunable; it therefore promises to be a versatile light-matter interface for local quantum processing applications.

  12. Single-photon emission from InAsP quantum dots embedded in density-controlled InP nanowires

    NASA Astrophysics Data System (ADS)

    Yanase, Shougo; Sasakura, Hirotaka; Hara, Shinjiro; Motohisa, Junichi

    2017-04-01

    We attempted to control the density and size of InP-based nanowires (NWs) and nanowire quantum dots (NW-QDs) during selective-area metalorganic vapor phase epitaxy. InP nanowire arrays with a 5 µm pitch and an average NW diameter d of 67 nm were successfully grown by optimization of growth conditions. InAsP quantum dots were embedded in these density-controlled InP NW arrays, and clear single-photon emission and exciton-biexciton cascaded emission were confirmed by excitation-dependent photoluminescence and photon correlation measurements.

  13. Quantum key distribution over a 72 dB channel loss using ultralow dark count superconducting single-photon detectors.

    PubMed

    Shibata, Hiroyuki; Honjo, Toshimori; Shimizu, Kaoru

    2014-09-01

    We report the first quantum key distribution (QKD) experiment over a 72 dB channel loss using superconducting nanowire single-photon detectors (SSPD, SNSPD) with the dark count rate (DCR) of 0.01 cps. The DCR of the SSPD, which is dominated by the blackbody radiation at room temperature, is blocked by introducing cold optical bandpass filter. We employ the differential phase shift QKD (DPS-QKD) scheme with a 1 GHz system clock rate. The quantum bit error rate (QBER) below 3% is achieved when the length of the dispersion shifted fiber (DSF) is 336 km (72 dB loss), which is low enough to generate secure keys.

  14. An electrically driven quantum dot-in-nanowire visible single photon source operating up to 150 K

    NASA Astrophysics Data System (ADS)

    Deshpande, Saniya; Bhattacharya, Pallab

    2013-12-01

    We demonstrate electrically pumped single photon emission up to 150 K from a single InGaN quantum dot embedded in a GaN nanowire junction diode. The InGaN dot-in-nanowire p-n junctions were grown on silicon by molecular beam epitaxy. The exciton electroluminescence from individual dot-in-nanowires is in the green spectral range (λ ˜ 520 nm) and is detectable up to 150 K. Second order autocorrelation measurements performed at the exciton energy at an ambient temperature of 125 K show a background corrected g(2)(0) equal to 0.35, indicating dominant single photon emission. The steady state nanowire temperature under these conditions is estimated to be 150 K due to Joule heating induced by the large nanowire series resistance. Time resolved photoluminescence measurements yield an exciton radiative lifetime of 1.1 ns.

  15. An electrically driven quantum dot-in-nanowire visible single photon source operating up to 150 K

    SciTech Connect

    Deshpande, Saniya; Bhattacharya, Pallab

    2013-12-09

    We demonstrate electrically pumped single photon emission up to 150 K from a single InGaN quantum dot embedded in a GaN nanowire junction diode. The InGaN dot-in-nanowire p-n junctions were grown on silicon by molecular beam epitaxy. The exciton electroluminescence from individual dot-in-nanowires is in the green spectral range (λ ∼ 520 nm) and is detectable up to 150 K. Second order autocorrelation measurements performed at the exciton energy at an ambient temperature of 125 K show a background corrected g{sup (2)}(0) equal to 0.35, indicating dominant single photon emission. The steady state nanowire temperature under these conditions is estimated to be 150 K due to Joule heating induced by the large nanowire series resistance. Time resolved photoluminescence measurements yield an exciton radiative lifetime of 1.1 ns.

  16. Linear optical quantum metrology with single photons: exploiting spontaneously generated entanglement to beat the shot-noise limit.

    PubMed

    Motes, Keith R; Olson, Jonathan P; Rabeaux, Evan J; Dowling, Jonathan P; Olson, S Jay; Rohde, Peter P

    2015-05-01

    Quantum number-path entanglement is a resource for supersensitive quantum metrology and in particular provides for sub-shot-noise or even Heisenberg-limited sensitivity. However, such number-path entanglement has been thought to be resource intensive to create in the first place--typically requiring either very strong nonlinearities, or nondeterministic preparation schemes with feedforward, which are difficult to implement. Very recently, arising from the study of quantum random walks with multiphoton walkers, as well as the study of the computational complexity of passive linear optical interferometers fed with single-photon inputs, it has been shown that such passive linear optical devices generate a superexponentially large amount of number-path entanglement. A logical question to ask is whether this entanglement may be exploited for quantum metrology. We answer that question here in the affirmative by showing that a simple, passive, linear-optical interferometer--fed with only uncorrelated, single-photon inputs, coupled with simple, single-mode, disjoint photodetection--is capable of significantly beating the shot-noise limit. Our result implies a pathway forward to practical quantum metrology with readily available technology.

  17. Fiber-coupled quantum-communications receiver based on two NbN superconducting single-photon detectors

    NASA Astrophysics Data System (ADS)

    Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Latta, C.; Zwiller, V.; Pearlman, A.; Cross, A.; Korneev, A.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol'tsman, G.; Verevkin, A.; Currie, M.; Sobolewski, R.

    2005-09-01

    We present the design and performance of a novel, two-channel single-photon receiver, based on two fiber-coupled NbN superconducting single-photon detectors (SSPDs). The SSPDs are nanostructured superconducting meanders covering an area of 100 μm2 and are known for ultrafast and efficient counting of single, visible-to-infrared photons. Their operation has been explained within a phenomenological hot-electron photoresponse model. Our receiver is intended for fiber-based quantum cryptography and communication systems, operational at near-infrared (NIR) telecommunication wavelengths, λ = 1.3 μm and λ = 1.55 μm. Coupling between the NbN detector and a single-mode optical fiber was achieved using a specially designed, micromechanical photoresist ring, positioned directly over the SSPD active area. The positioning accuracy of the ring was below 1 μm. The receiver with SSPDs was placed (immersed) in a standard liquid-helium transport Dewar and kept without interruption for over two months at 4.2 K. At the same time, the optical fiber inputs and electrical outputs were kept at room temperature. Our best system reached a system quantum efficiency of up to 0.3 % in the NIR radiation range, with the detector coupling efficiency of about 30 %. The response time was measured to be about 250 ps and was limited by our read-out electronics. The measured jitter was close to 35 ps. The presented performance parameters show that our NIR single photon detectors are suitable for practical quantum cryptography and for applications in quantum-correlation experiments.

  18. On-Demand Single Photons with High Extraction Efficiency and Near-Unity Indistinguishability from a Resonantly Driven Quantum Dot in a Micropillar.

    PubMed

    Ding, Xing; He, Yu; Duan, Z-C; Gregersen, Niels; Chen, M-C; Unsleber, S; Maier, S; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2016-01-15

    Scalable photonic quantum technologies require on-demand single-photon sources with simultaneously high levels of purity, indistinguishability, and efficiency. These key features, however, have only been demonstrated separately in previous experiments. Here, by s-shell pulsed resonant excitation of a Purcell-enhanced quantum dot-micropillar system, we deterministically generate resonance fluorescence single photons which, at π pulse excitation, have an extraction efficiency of 66%, single-photon purity of 99.1%, and photon indistinguishability of 98.5%. Such a single-photon source for the first time combines the features of high efficiency and near-perfect levels of purity and indistinguishabilty, and thus opens the way to multiphoton experiments with semiconductor quantum dots.

  19. Single-photon sources

    NASA Astrophysics Data System (ADS)

    Lounis, Brahim; Orrit, Michel

    2005-05-01

    The concept of the photon, central to Einstein's explanation of the photoelectric effect, is exactly 100 years old. Yet, while photons have been detected individually for more than 50 years, devices producing individual photons on demand have only appeared in the last few years. New concepts for single-photon sources, or 'photon guns', have originated from recent progress in the optical detection, characterization and manipulation of single quantum objects. Single emitters usually deliver photons one at a time. This so-called antibunching of emitted photons can arise from various mechanisms, but ensures that the probability of obtaining two or more photons at the same time remains negligible. We briefly recall basic concepts in quantum optics and discuss potential applications of single-photon states to optical processing of quantum information: cryptography, computing and communication. A photon gun's properties are significantly improved by coupling it to a resonant cavity mode, either in the Purcell or strong-coupling regimes. We briefly recall early production of single photons with atomic beams, and the operation principles of macroscopic parametric sources, which are used in an overwhelming majority of quantum-optical experiments. We then review the photophysical and spectroscopic properties and compare the advantages and weaknesses of various single nanometre-scale objects used as single-photon sources: atoms or ions in the gas phase and, in condensed matter, organic molecules, defect centres, semiconductor nanocrystals and heterostructures. As new generations of sources are developed, coupling to cavities and nano-fabrication techniques lead to improved characteristics, delivery rates and spectral ranges. Judging from the brisk pace of recent progress, we expect single photons to soon proceed from demonstrations to applications and to bring with them the first practical uses of quantum information.

  20. Quantum Key Distribution with High-Speed Superconducting Single-Photon Detectors

    DTIC Science & Technology

    2007-05-01

    based QKD [2,3], with high detection efficiency (~40 % at 850 nm) and low dark counts (~100 Hz). For near - infrared wavelengths such as the standard...to near - infrared ,” Appl. Phys. Lett. 80, 4687 (2002). [7] R. H. Hadfield et al. “Single photon source characterization with a superconducting single...efficiency at the wavelength of interest. At wavelengths below 1000 nm Silicon Avalanche Photodiodes (Si APDs) are the detector of choice for fiber

  1. Efficient single-photon source based on a deterministically fabricated single quantum dot - microstructure with backside gold mirror

    NASA Astrophysics Data System (ADS)

    Fischbach, Sarah; Kaganskiy, Arsenty; Tauscher, Esra Burcu Yarar; Gericke, Fabian; Thoma, Alexander; Schmidt, Ronny; Strittmatter, André; Heindel, Tobias; Rodt, Sven; Reitzenstein, Stephan

    2017-07-01

    We present an efficient broadband single-photon source which is fabricated by a flip-chip gold-bonding technique and in-situ electron beam lithography. The device comprises a single InGaAs quantum dot that is centered at the bottom of a monolithic mesa structure and located above a gold mirror for enhanced photon-extraction efficiency. We show a photon-extraction efficiency of ηex t=(18 ±2 ) % into a numerical aperture of 0.4 and a high suppression of multi-photon events from this source with g(2 )(0 )=0.015 ±0.009 . Our deterministic device with a backside gold mirror can be combined with electrical contacts and piezo-tuning capabilities in future refinements, which represents an important step towards a spectrally tunable plug-and-play quantum-light source with broadband enhancement for photonic quantum networks.

  2. Transparency and slow light in a four-level quantum system near a plasmonic nanostructure

    NASA Astrophysics Data System (ADS)

    Evangelou, Sofia; Yannopapas, Vassilios; Paspalakis, Emmanuel

    2012-11-01

    We study theoretically the effects of a plasmonic nanostructure on the linear absorption and dispersion spectrum of a four-level double- V-type quantum system. In the quantum system under study one V-type transition is influenced by the interaction with surface plasmons while the other V-type transition interacts with free-space vacuum. As plasmonic nanostructure we consider a two-dimensional array of metal-coated dielectric nanospheres. We analyze the optical properties of a linearly polarized laser field that couples the lowest state with the upper states in the free-space transitions. We show that, due to the presence of the plasmonic nanostructure, effects of optical transparency are created. These effects are also complemented by the existence of slow light.

  3. Control of the absorption of a four-level quantum system near a plasmonic nanostructure

    NASA Astrophysics Data System (ADS)

    Carreño, F.; Antón, M. A.; Yannopapas, V.; Paspalakis, E.

    2017-05-01

    We study the optical response of a four-level double-V-type quantum system which interacts simultaneously with probe and pump laser fields and is located near a two-dimensional array of metal-coated dielectric nanospheres. By considering different coupling configurations for the pump/probe laser fields and analyzing the resulting probe absorption spectrum we reveal a variety of phenomena, such as huge enhancement of the absorption at the central line, gain without inversion, and a phase-dependent absorption spectrum. We also show that the enhancement of probe absorption or the gain can be controlled by varying the distance of the quantum system from the plasmonic nanostructure, the intensity of the pump field(s), and, when applicable, their relative phase. Our results can find applications in on-chip nanoscale photonic devices.

  4. Control of resonance fluorescence of a four-level quantum emitter near a plasmonic nanostructure

    NASA Astrophysics Data System (ADS)

    Carreño, F.; Antón, M. A.; Yannopapas, V.; Paspalakis, E.

    2017-04-01

    We present a theoretical study of the resonance fluorescence of a four-level double-V -type quantum emitter near a plasmonic nanostructure. The quantum system interacts with two orthogonal circularly polarized laser fields with the same frequency and intensity, but with different phases. For the plasmonic nanostructure we consider a two-dimensional array of metal-coated dielectric nanospheres. We show that the presence of the plasmonic nanostructure leads to strong modification of both the resonance fluorescence spectrum and the transition from antibunching to bunching for the fluorescent photons. In addition, we show that both the resonance fluorescence spectrum and the second-order correlation function are strongly phase-dependent so that the relative phase of laser fields can be used for the efficient control of the resonance fluorescence characteristics. The results are explained by using a dressed-state picture.

  5. High-fidelity teleportation of continuous-variable quantum states using delocalized single photons.

    PubMed

    Andersen, Ulrik L; Ralph, Timothy C

    2013-08-02

    Traditional continuous-variable teleportation can only approach unit fidelity in the limit of an infinite (and unphysical) amount of squeezing. We describe a new method for continuous-variable teleportation that approaches unit fidelity with finite resources. The protocol is not based on squeezed states as in traditional teleportation but on an ensemble of single photon entangled states. We characterize the teleportation scheme with coherent states, mesoscopic superposition states, and two-mode squeezed states and we find several situations in which near-unity teleportation fidelity can be obtained with modest resources.

  6. Several experimental realizations of symmetric phase-covariant quantum cloners of single-photon qubits

    SciTech Connect

    Soubusta, Jan; Cernoch, Antonin; Bartuskova, Lucie; Fiurasek, Jaromir; Dusek, Miloslav

    2007-10-15

    We compare several optical implementations of phase-covariant cloning machines. The experiments are based on copying of the polarization state of a single photon in bulk optics by a special unbalanced beam splitter or by a balanced beam splitter accompanied by a state filtering. Also the all-fiber-based setup is discussed, where the information is encoded into spatial modes, i.e., the photon can propagate through two optical fibers. Each of the four implementations possesses some advantages and disadvantages that are discussed.

  7. Two-photon interference using background-free quantum frequency conversion of single photons emitted by an InAs quantum dot.

    PubMed

    Ates, Serkan; Agha, Imad; Gulinatti, Angelo; Rech, Ivan; Rakher, Matthew T; Badolato, Antonio; Srinivasan, Kartik

    2012-10-05

    We show that quantum frequency conversion (QFC) can overcome the spectral distinguishability common to inhomogeneously broadened solid-state quantum emitters. QFC is implemented by combining single photons from an InAs/GaAs quantum dot (QD) at 980 nm with a 1550 nm pump laser in a periodically poled lithium niobate (PPLN) waveguide to generate photons at 600 nm with a signal-to-background ratio exceeding 100:1. Photon correlation and two-photon interference measurements confirm that both the single photon character and wave packet interference of individual QD states are preserved during frequency conversion. Finally, we convert two spectrally separate QD transitions to the same wavelength in a single PPLN waveguide and show that the resulting field exhibits nonclassical two-photon interference.

  8. Heterostructures with CdTe/ZnTe quantum dots for single photon emitters grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Sorokin, S. V.; Sedova, I. V.; Gronin, S. V.; Belyaev, K. G.; Rakhlin, M. V.; Toropov, A. A.; Mukhin, I. S.; Ivanov, S. V.

    2016-12-01

    We report on the molecular beam epitaxy (MBE) of heterostructures with CdTe/ZnTe quantum dots (QDs) with relatively low surface density, which could be used as single-photon emitters. The QDs were formed on the surface of a 3.1- to 4.5-monolayer-thick two-dimensional strained CdTe layer by depositing amorphous Te layer and its fast thermal desorption. Subsequent thermal annealing of the surface with QDs in the absence of external Te flux led to strong broadening and short-wavelength shift of the QD photoluminescence (PL) peak. Measurement of the micro-PL spectra of individual CdTe/ZnTe quantum dots in fabricated mesastructures with a diameter of 200—1000 nm allowed estimation of the QD surface density as 1010 cm-2.

  9. Information Leakage Problem in Efficient Bidirectional Quantum Secure Direct Communication with Single Photons in Both Polarization and Spatial-Mode Degrees of Freedom

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-Hao; Chen, Han-Wu; Liu, Wen-Jie

    2016-11-01

    The information leakage problem in the efficient bidirectional quantum secure direct communication protocol with single photons in both polarization and spatial-mode degrees of freedom is pointed out. Next, a way to revise this protocol to a truly secure one is given. We hope people pay more attention to the information leakage problem in order to design truly secure quantum communication protocols.

  10. Realization of a Cascaded Quantum System: Heralded Absorption of a Single Photon Qubit by a Single-Electron Charged Quantum Dot.

    PubMed

    Delteil, Aymeric; Sun, Zhe; Fält, Stefan; Imamoğlu, Atac

    2017-04-28

    Photonic losses pose a major limitation for the implementation of a quantum state transfer between nodes of a quantum network. A measurement that heralds a successful transfer without revealing any information about the qubit may alleviate this limitation. Here, we demonstrate the heralded absorption of a single photonic qubit, generated by a single neutral quantum dot, by a single-electron charged quantum dot that is located 5 m away. The transfer of quantum information to the spin degree of freedom takes place upon the emission of a photon; for a properly chosen or prepared quantum dot, the detection of this photon yields no information about the qubit. We show that this process can be combined with local operations optically performed on the destination node by measuring classical correlations between the absorbed photon color and the final state of the electron spin. Our work suggests alternative avenues for the realization of quantum information protocols based on cascaded quantum systems.

  11. Realization of a Cascaded Quantum System: Heralded Absorption of a Single Photon Qubit by a Single-Electron Charged Quantum Dot

    NASA Astrophysics Data System (ADS)

    Delteil, Aymeric; Sun, Zhe; Fält, Stefan; Imamoǧlu, Atac

    2017-04-01

    Photonic losses pose a major limitation for the implementation of a quantum state transfer between nodes of a quantum network. A measurement that heralds a successful transfer without revealing any information about the qubit may alleviate this limitation. Here, we demonstrate the heralded absorption of a single photonic qubit, generated by a single neutral quantum dot, by a single-electron charged quantum dot that is located 5 m away. The transfer of quantum information to the spin degree of freedom takes place upon the emission of a photon; for a properly chosen or prepared quantum dot, the detection of this photon yields no information about the qubit. We show that this process can be combined with local operations optically performed on the destination node by measuring classical correlations between the absorbed photon color and the final state of the electron spin. Our work suggests alternative avenues for the realization of quantum information protocols based on cascaded quantum systems.

  12. Quantum storage of heralded single photons in a praseodymium-doped crystal.

    PubMed

    Rieländer, Daniel; Kutluer, Kutlu; Ledingham, Patrick M; Gündoğan, Mustafa; Fekete, Julia; Mazzera, Margherita; de Riedmatten, Hugues

    2014-01-31

    We report on experiments demonstrating the reversible mapping of heralded single photons to long-lived collective optical atomic excitations stored in a Pr3+:Y2SiO5 crystal. A cavity-enhanced spontaneous down-conversion source is employed to produce widely nondegenerate narrow-band (≈2  MHz) photon pairs. The idler photons, whose frequency is compatible with telecommunication optical fibers, are used to herald the creation of the signal photons, compatible with the Pr3+ transition. The signal photons are stored and retrieved using the atomic frequency comb protocol. We demonstrate storage times up to 4.5  μs while preserving nonclassical correlations between the heralding and the retrieved photon. This is more than 20 times longer than in previous realizations in solid state devices, and implemented in a system ideally suited for the extension to spin-wave storage.

  13. Free space quantum key distribution over 500 meters using electrically driven quantum dot single-photon sources—a proof of principle experiment

    NASA Astrophysics Data System (ADS)

    Rau, Markus; Heindel, Tobias; Unsleber, Sebastian; Braun, Tristan; Fischer, Julian; Frick, Stefan; Nauerth, Sebastian; Schneider, Christian; Vest, Gwenaelle; Reitzenstein, Stephan; Kamp, Martin; Forchel, Alfred; Höfling, Sven; Weinfurter, Harald

    2014-04-01

    Highly efficient single-photon sources (SPS) can increase the secure key rate of quantum key distribution (QKD) systems compared to conventional attenuated laser systems. Here we report on a free space QKD test using an electrically driven quantum dot single-photon source (QD SPS) that does not require a separate laser setup for optical pumping and thus allows for a simple and compact SPS QKD system. We describe its implementation in our 500 m free space QKD system in downtown Munich. Emulating a BB84 protocol operating at a repetition rate of 125 MHz, we could achieve sifted key rates of 5-17 kHz with error ratios of 6-9% and {{\\text{g}}^{(2)}}(0)-values of 0.39-0.76.

  14. Efficiency enhancement for the orbital angular momentum photon quantum interface via single photon frequency upconversion

    NASA Astrophysics Data System (ADS)

    Wu, Wen-jie; Ma, Jian-hui; Pan, Hai-feng; Wu, E.; Chen, Huai-xi; Dismas, K. Choge; Liang, Wan-guo

    2017-03-01

    As the application of orbital angular momentum ( OAM) of photon quantum in quantum communication, the OAM photon quantum interface for the transmission wavelength from the telecom communication quantum information storage in visible regime is required. Here we demonstrate the efficiency enhancement for the OAM photon quantum interface based on the frequency upconversion from telecom wavelength to visible regime by sum-frequency generation. The infrared photons at 1 558 nm carrying different OAM values could be converted to the visible regime at 622.2 nm with the optimal efficiency via adjusting the pump beam waist radius and intensity.

  15. Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation

    NASA Astrophysics Data System (ADS)

    Ide, Toshiki; Hofmann, Holger F.

    2007-06-01

    The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the N -photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.

  16. Reducing Phonon-Induced Decoherence in Solid-State Single-Photon Sources with Cavity Quantum Electrodynamics.

    PubMed

    Grange, T; Somaschi, N; Antón, C; De Santis, L; Coppola, G; Giesz, V; Lemaître, A; Sagnes, I; Auffèves, A; Senellart, P

    2017-06-23

    Solid-state emitters are excellent candidates for developing integrated sources of single photons. Yet, phonons degrade the photon indistinguishability both through pure dephasing of the zero-phonon line and through phonon-assisted emission. Here, we study theoretically and experimentally the indistinguishability of photons emitted by a semiconductor quantum dot in a microcavity as a function of temperature. We show that a large coupling to a high quality factor cavity can simultaneously reduce the effect of both phonon-induced sources of decoherence. It first limits the effect of pure dephasing on the zero-phonon line with indistinguishabilities above 97% up to 18 K. Moreover, it efficiently redirects the phonon sidebands into the zero-phonon line and brings the indistinguishability of the full emission spectrum from 87% (24%) without cavity effect to more than 99% (76%) at 0K (20K). We provide guidelines for optimal cavity designs that further minimize the phonon-induced decoherence.

  17. Reducing Phonon-Induced Decoherence in Solid-State Single-Photon Sources with Cavity Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Grange, T.; Somaschi, N.; Antón, C.; De Santis, L.; Coppola, G.; Giesz, V.; Lemaître, A.; Sagnes, I.; Auffèves, A.; Senellart, P.

    2017-06-01

    Solid-state emitters are excellent candidates for developing integrated sources of single photons. Yet, phonons degrade the photon indistinguishability both through pure dephasing of the zero-phonon line and through phonon-assisted emission. Here, we study theoretically and experimentally the indistinguishability of photons emitted by a semiconductor quantum dot in a microcavity as a function of temperature. We show that a large coupling to a high quality factor cavity can simultaneously reduce the effect of both phonon-induced sources of decoherence. It first limits the effect of pure dephasing on the zero-phonon line with indistinguishabilities above 97% up to 18 K. Moreover, it efficiently redirects the phonon sidebands into the zero-phonon line and brings the indistinguishability of the full emission spectrum from 87% (24%) without cavity effect to more than 99% (76%) at 0K (20K). We provide guidelines for optimal cavity designs that further minimize the phonon-induced decoherence.

  18. Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation

    SciTech Connect

    Ide, Toshiki; Hofmann, Holger F.

    2007-06-15

    The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the N-photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.

  19. Intrinsic imperfection of self-differencing single-photon detectors harms the security of high-speed quantum cryptography systems

    NASA Astrophysics Data System (ADS)

    Jiang, Mu-Sheng; Sun, Shi-Hai; Tang, Guang-Zhao; Ma, Xiang-Chun; Li, Chun-Yan; Liang, Lin-Mei

    2013-12-01

    Thanks to the high-speed self-differencing single-photon detector (SD-SPD), the secret key rate of quantum key distribution (QKD), which can, in principle, offer unconditionally secure private communications between two users (Alice and Bob), can exceed 1 Mbit/s. However, the SD-SPD may contain loopholes, which can be exploited by an eavesdropper (Eve) to hack into the unconditional security of the high-speed QKD systems. In this paper, we analyze the fact that the SD-SPD can be remotely controlled by Eve in order to spy on full information without being discovered, then proof-of-principle experiments are demonstrated. Here, we point out that this loophole is introduced directly by the operating principle of the SD-SPD, thus, it cannot be removed, except for the fact that some active countermeasures are applied by the legitimate parties.

  20. Tuning the growth for a selective nucleation of chains of Quantum Dots behaving as single photon emitters

    NASA Astrophysics Data System (ADS)

    Latini, V.; Tisbi, E.; Placidi, E.; Patella, F.; Biccari, F.; Gurioli, M.; Vinattieri, A.; Arciprete, F.

    2017-01-01

    Single and two-layer InAs/GaAs(001) samples were grown in a Molecular Beam Epitaxy chamber under critical conditions, leading to the selective growth of self-assembled InAs Quantum Dot chains over mounded GaAs surfaces. Changing the thickness of the spacer layer and the InAs deposition made it possible to tune the nucleation of 2-fold or single chains in the second layer. Finite Element Method simulations evidenced the major role of the strain field in favoring the formation of single stacked chains. On the other hand, tuning properly the As4/In flux ratio contributed to improving the QD ordering along the chains. Microphotoluminescence experiments demonstrated single photon emission properties of the observed QDs. Our growth approach did not degrade the optical quality of the InAs QDs, allowing a significant spatial correlation between the QDs aligned along the chain.

  1. Cascaded emission of linearly polarized single photons from positioned InP/GaInP quantum dots

    SciTech Connect

    Braun, T.; Unsleber, S.; Baumann, V.; Schneider, C.; Höfling, S.; Kamp, M.; Gschrey, M.; Rodt, S.; Reitzenstein, S.

    2013-11-04

    We report on the optical characterization of site-controlled InP/GaInP quantum dots (QDs). Spatially resolved low temperature cathodoluminescence proves the long-range ordering of the buried emitters, revealing a yield of ∼90% of optically active, positioned QDs and a strong suppression of emitters on interstitial positions. The emission of single QDs shows a pronounced degree of linear polarization along the [0,−1,1] crystal axis with an average degree of polarization of 94%. Photon correlation measurements of the emission from a single QD indicate the single-photon character of the exciton and biexciton emission lines as well as the cascaded nature of the photon pair.

  2. Diamond chip under single-photon driving as a high spatial resolution quantum magnetometer and electrometer

    NASA Astrophysics Data System (ADS)

    Tsukanov, Alexander V.; Kateev, Igor Y.

    2016-12-01

    The problem of practical realization of a compact sensing device with high-spatial resolution is addressed. The principle of external field measuring uses analysis of transmission or reflection spectra from a diamond microstructure composed of three-microring optical resonators. Due to Zeeman and Stark shifts of energy levels of NV-centers formed in the microring edge the hybrid electron-photon spectrum changes depending on the strength and direction of magnetic and electric fields, respectively. A probe laser with a tunable wavelength excites the structure in a single-photon regime and its response enables one to detect the fields via spectral behavior. The model of the sensor dynamics accounts for both coherent driving and incoherent processes (center relaxation, dephasing and photon leakage) in terms of Lindblad formalism. With use of the finite-difference time-domain numerical method a three-ring spectrum is calculated and eigenmodes close to NV-center zero-phonon line are found. Electromagnetic field shows whispering-gallery behavior, so NV-center is coupled to a common three-ring mode antinode. As we show in the steady-state regime our approach gives the possibility of external fields measuring in a large intensity range with high sensitivity.

  3. Quantum logical gates with four-level superconducting quantum interference devices coupled to a superconducting resonator

    SciTech Connect

    He Xiaoling; Luo Junyan; Yang Chuiping; Li Sheng; Han Siyuan

    2010-08-15

    We propose a way for realizing a two-qubit controlled phase gate with superconducting quantum interference devices (SQUIDs) coupled to a superconducting resonator. In this proposal, the two lowest levels of each SQUID serve as the logical states and two intermediate levels of each SQUID are used for the gate realization. We show that neither adjustment of SQUID level spacings during the gate operation nor uniformity in SQUID parameters is required by this proposal. In addition, this proposal does not require the adiabatic passage or a second-order detuning and thus the gate is much faster.

  4. On-chip beamsplitter operation on single photons from quasi-resonantly excited quantum dots embedded in GaAs rib waveguides

    SciTech Connect

    Rengstl, U.; Schwartz, M.; Herzog, T.; Hargart, F.; Paul, M.; Portalupi, S. L.; Jetter, M.; Michler, P.

    2015-07-13

    We present an on-chip beamsplitter operating on a single-photon level by means of a quasi-resonantly driven InGaAs/GaAs quantum dot. The single photons are guided by rib waveguides and split into two arms by an evanescent field coupler. Although the waveguides themselves support the fundamental TE and TM modes, the measured degree of polarization (∼90%) reveals the main excitation and propagation of the TE mode. We observe the preserved single-photon nature of a quasi-resonantly excited quantum dot by performing a cross-correlation measurement on the two output arms of the beamsplitter. Additionally, the same quantum dot is investigated under resonant excitation, where the same splitting ratio is observed. An autocorrelation measurement with an off-chip beamsplitter on a single output arm reveal the single-photon nature after evanescent coupling inside the on-chip splitter. Due to their robustness, adjustable splitting ratio, and their easy implementation, rib waveguide beamsplitters with embedded quantum dots provide a promising step towards fully integrated quantum circuits.

  5. Telecommunication Wavelength-Band Single-Photon Emission from Single Large InAs Quantum Dots Nucleated on Low-Density Seed Quantum Dots.

    PubMed

    Chen, Ze-Sheng; Ma, Ben; Shang, Xiang-Jun; He, Yu; Zhang, Li-Chun; Ni, Hai-Qiao; Wang, Jin-Liang; Niu, Zhi-Chuan

    2016-12-01

    Single-photon emission in the telecommunication wavelength band is realized with self-assembled strain-coupled bilayer InAs quantum dots (QDs) embedded in a planar microcavity on GaAs substrate. Low-density large QDs in the upper layer active for ~1.3 μm emission are fabricated by precisely controlling the indium deposition amount and applying a gradient indium flux in both QD layers. Time-resolved photoluminescence (PL) intensity suggested that the radiative lifetime of their exciton emission is 1.5~1.6 ns. The second-order correlation function of g (2)(0) < 0.5 which demonstrates a pure single-photon emission.

  6. Quantum scattering theory of a single-photon Fock state in three-dimensional spaces.

    PubMed

    Liu, Jingfeng; Zhou, Ming; Yu, Zongfu

    2016-09-15

    A quantum scattering theory is developed for Fock states scattered by two-level systems in three-dimensional free space. It is built upon the one-dimensional scattering theory developed in waveguide quantum electrodynamics. The theory fully quantizes the incident light as Fock states and uses a non-perturbative method to calculate the scattering matrix.

  7. Room Temperature Single-Photon Emission from Individual Perovskite Quantum Dots.

    PubMed

    Park, Young-Shin; Guo, Shaojun; Makarov, Nikolay S; Klimov, Victor I

    2015-10-27

    Lead-halide-based perovskites have been the subject of numerous recent studies largely motivated by their exceptional performance in solar cells. Electronic and optical properties of these materials have been commonly controlled by varying the composition (e.g., the halide component) and/or crystal structure. Use of nanostructured forms of perovskites can provide additional means for tailoring their functionalities via effects of quantum confinement and wave function engineering. Furthermore, it may enable applications that explicitly rely on the quantum nature of electronic excitations. Here, we demonstrate that CsPbX3 quantum dots (X = I, Br) can serve as room-temperature sources of quantum light, as indicated by strong photon antibunching detected in single-dot photoluminescence measurements. We explain this observation by the presence of fast nonradiative Auger recombination, which renders multiexciton states virtually nonemissive and limits the fraction of photon coincidence events to ∼6% on average. We analyze limitations of these quantum dots associated with irreversible photodegradation and fluctuations ("blinking") of the photoluminescence intensity. On the basis of emission intensity-lifetime correlations, we assign the "blinking" behavior to random charging/discharging of the quantum dot driven by photoassisted ionization. This study suggests that perovskite quantum dots hold significant promise for applications such as quantum emitters; however, to realize this goal, one must resolve the problems of photochemical stability and photocharging. These problems are largely similar to those of more traditional quantum dots and, hopefully, can be successfully resolved using advanced methodologies developed over the years in the field of colloidal nanostructures.

  8. Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling

    PubMed Central

    Birowosuto, Muhammad Danang; Sumikura, Hisashi; Matsuo, Shinji; Taniyama, Hideaki; van Veldhoven, Peter J.; Nötzel, Richard; Notomi, Masaya

    2012-01-01

    High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres. PMID:22432053

  9. Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling.

    PubMed

    Birowosuto, Muhammad Danang; Sumikura, Hisashi; Matsuo, Shinji; Taniyama, Hideaki; van Veldhoven, Peter J; Nötzel, Richard; Notomi, Masaya

    2012-01-01

    High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres.

  10. Heralded high-efficiency quantum repeater with atomic ensembles assisted by faithful single-photon transmission

    PubMed Central

    Li, Tao; Deng, Fu-Guo

    2015-01-01

    Quantum repeater is one of the important building blocks for long distance quantum communication network. The previous quantum repeaters based on atomic ensembles and linear optical elements can only be performed with a maximal success probability of 1/2 during the entanglement creation and entanglement swapping procedures. Meanwhile, the polarization noise during the entanglement distribution process is harmful to the entangled channel created. Here we introduce a general interface between a polarized photon and an atomic ensemble trapped in a single-sided optical cavity, and with which we propose a high-efficiency quantum repeater protocol in which the robust entanglement distribution is accomplished by the stable spatial-temporal entanglement and it can in principle create the deterministic entanglement between neighboring atomic ensembles in a heralded way as a result of cavity quantum electrodynamics. Meanwhile, the simplified parity-check gate makes the entanglement swapping be completed with unity efficiency, other than 1/2 with linear optics. We detail the performance of our protocol with current experimental parameters and show its robustness to the imperfections, i.e., detuning and coupling variation, involved in the reflection process. These good features make it a useful building block in long distance quantum communication. PMID:26502993

  11. Heralded high-efficiency quantum repeater with atomic ensembles assisted by faithful single-photon transmission.

    PubMed

    Li, Tao; Deng, Fu-Guo

    2015-10-27

    Quantum repeater is one of the important building blocks for long distance quantum communication network. The previous quantum repeaters based on atomic ensembles and linear optical elements can only be performed with a maximal success probability of 1/2 during the entanglement creation and entanglement swapping procedures. Meanwhile, the polarization noise during the entanglement distribution process is harmful to the entangled channel created. Here we introduce a general interface between a polarized photon and an atomic ensemble trapped in a single-sided optical cavity, and with which we propose a high-efficiency quantum repeater protocol in which the robust entanglement distribution is accomplished by the stable spatial-temporal entanglement and it can in principle create the deterministic entanglement between neighboring atomic ensembles in a heralded way as a result of cavity quantum electrodynamics. Meanwhile, the simplified parity-check gate makes the entanglement swapping be completed with unity efficiency, other than 1/2 with linear optics. We detail the performance of our protocol with current experimental parameters and show its robustness to the imperfections, i.e., detuning and coupling variation, involved in the reflection process. These good features make it a useful building block in long distance quantum communication.

  12. Implementation of single-photon quantum routing and decoupling using a nitrogen-vacancy center and a whispering-gallery-mode resonator-waveguide system.

    PubMed

    Cao, Cong; Duan, Yu-Wen; Chen, Xi; Zhang, Ru; Wang, Tie-Jun; Wang, Chuan

    2017-07-24

    Quantum router is a key element needed for the construction of future complex quantum networks. However, quantum routing with photons, and its inverse, quantum decoupling, are difficult to implement as photons do not interact, or interact very weakly in nonlinear media. In this paper, we investigate the possibility of implementing photonic quantum routing based on effects in cavity quantum electrodynamics, and present a scheme for single-photon quantum routing controlled by the other photon using a hybrid system consisting of a single nitrogen-vacancy (NV) center coupled with a whispering-gallery-mode resonator-waveguide structure. Different from the cases in which classical information is used to control the path of quantum signals, both the control and signal photons are quantum in our implementation. Compared with the probabilistic quantum routing protocols based on linear optics, our scheme is deterministic and also scalable to multiple photons. We also present a scheme for single-photon quantum decoupling from an initial state with polarization and spatial-mode encoding, which can implement an inverse operation to the quantum routing. We discuss the feasibility of our schemes by considering current or near-future techniques, and show that both the schemes can operate effectively in the bad-cavity regime. We believe that the schemes could be key building blocks for future complex quantum networks and large-scale quantum information processing.

  13. Device-independent quantum key distribution using single-photon entanglement

    NASA Astrophysics Data System (ADS)

    Kamaruddin, S.; Shaari, J. S.

    2015-04-01

    Quantum key distribution (QKD) with security features based on the notion of nonlocality has provided valuable insights into the possibility of device-independent scenarios. The essential resource for nonlocality in Nature described by quantum physics has been mainly associated with entanglement of two particles or more, although it has been shown that nonlocality of a single particle is indeed possible. Here, we consider a quantum key distribution scheme based on Phys. Rev. A, 68 (2003) 012324 exploiting single-particle nonlocality testing to demonstrate its security. We present our analysis of security against individual attack within a device-independent scenario where Eve is constrained only by the no-signaling principle. We further consider a family of QKD protocols based on binary measurements and discuss the possibility of optimal scenarios.

  14. Quantum Optics with Superconducting Circuits: From Single Photons to Schrodinger Cats

    SciTech Connect

    Schoelkopf, Rob

    2013-01-09

    Over the last decade and a half, superconducting circuits have advanced to the point where we can generate and detect highly-entangled states, and perform universal quantum gates. Meanwhile, the coherence properties of these systems have improved more than 10,000-fold. I will describe recent experiments, such as the latest advance in coherence using a three-dimensional implementation of qubits interacting with microwave cavities, called “3D circuit QED.” The control and strong interactions possible in superconducting circuits make it possible to generate non-classical states of light, including large superpositions known as “Schrodinger cat” states. This field has many interesting prospects both for applications in quantum information processing, and fundamental investigations of the boundary between the macroscopic classical world and the microscopic world of the quantum.

  15. Highly efficient heralding of entangled single photons.

    PubMed

    Ramelow, Sven; Mech, Alexandra; Giustina, Marissa; Gröblacher, Simon; Wieczorek, Witlef; Beyer, Jörn; Lita, Adriana; Calkins, Brice; Gerrits, Thomas; Nam, Sae Woo; Zeilinger, Anton; Ursin, Rupert

    2013-03-25

    Single photons are an important prerequisite for a broad spectrum of quantum optical applications. We experimentally demonstrate a heralded single-photon source based on spontaneous parametric down-conversion in collinear bulk optics, and fiber-coupled bolometric transition-edge sensors. Without correcting for background, losses, or detection inefficiencies, we measure an overall heralding efficiency of 83%. By violating a Bell inequality, we confirm the single-photon character and high-quality entanglement of our heralded single photons which, in combination with the high heralding efficiency, are a necessary ingredient for advanced quantum communication protocols such as one-sided device-independent quantum key distribution.

  16. Quantum-tomographic cryptography with a semiconductor single-photon source

    SciTech Connect

    Kaszlikowski, D.; Yang, L.J.; Yong, L.S.; Willeboordse, F.H.; Kwek, L.C.

    2005-09-15

    We analyze the security of so-called quantum-tomographic cryptography with the source producing entangled photons via an experimental scheme proposed by Fattal et al. [Phys. Rev. Lett. 92, 37903 (2004)]. We determine the range of the experimental parameters for which the protocol is secure against the most general incoherent attacks.

  17. Deterministic coupling of a system of multiple quantum dots to a single photonic cavity mode

    NASA Astrophysics Data System (ADS)

    Lyasota, A.; Jarlov, C.; Gallo, P.; Rudra, A.; Dwir, B.; Kapon, E.

    2017-07-01

    We fabricated and studied a system comprising four site-controlled semiconductor quantum dots (QDs) embedded in a linear photonic crystal membrane cavity. The excellent position control and small spectral broadening permit coupling of the emission of all four QDs to the same photonic cavity modes. This is corroborated by co-polarization of the QD and cavity emission lines, as well as reduction in decay time, both with characteristic dependence on QD-cavity energy detuning. Scaling up to larger QD systems is discussed.

  18. Quantum versus semiclassical description of light interaction with atomic ensembles: Revision of the Maxwell-Bloch equations and single-photon superradiance

    NASA Astrophysics Data System (ADS)

    Svidzinsky, Anatoly A.; Zhang, Xiwen; Scully, Marlan O.

    2015-07-01

    Interaction of atoms with quantum states of light is a long-standing problem that apart from fundamental physics has potential applications for optical quantum-state storage, quantum communication, and quantum information. A fully quantum mechanical treatment of this problem is usually very complicated mathematically. Here we show, however, that quantum mechanical evolution equations describing single-photon emission (absorption) by atomic ensembles can be written in a form equivalent to the semiclassical Maxwell-Bloch equations. This connection allows us to find exact analytical solutions of the fully quantum mechanical problem. We also found that semiclassical Maxwell-Bloch equations should be written in a form different from those commonly used. Namely, the classical limit of the quantum problem gives a propagation equation with the Laplacian operator on the right-hand side rather than with the second-order time derivative.

  19. Phase dependence of optical bistability and multistability in a four-level quantum system near a plasmonic nanostructure

    SciTech Connect

    Asadpour, Seyyed Hossein; Rahimpour Soleimani, H.

    2016-01-14

    The optical bistability and multistability properties of a four-level quantum system near a plasmonic nanostructure embedded in a unidirectional ring cavity are studied theoretically. Two orthogonal circularly polarized laser fields with the same frequency, different phases and electric fields amplitude are interacted by four-level quantum system. It is found that in the presence of the plasmonic nanostructure, the bistable behaviors related to one of the laser fields propagating through the unidirectional ring cavity can be modified by relative phase and amplitude control of another laser fields. Our obtained results show that the optical bistability can be converted into the optical multistability by varying the value of distance between the quantum system and the surface of the plasmonic nanostructure. Moreover, it is shown that under specific condition related to the distance, the lasing without population inversion can be obtained.

  20. Single-photon emission of InAs/InP quantum dashes at 1.55 μm and temperatures up to 80 K

    SciTech Connect

    Dusanowski, Ł. Syperek, M.; Misiewicz, J.; Sęk, G.; Somers, A.; Kamp, M.; Höfling, S.; Reithmaier, J. P.

    2016-04-18

    We report on single photon emission from a self-assembled InAs/InGaAlAs/InP quantum dash emitting at 1.55 μm at the elevated temperatures. The photon auto-correlation histograms of the emission from a charged exciton indicate clear antibunching dips with as-measured g{sup (2)}(0) values significantly below 0.5 recorded at temperatures up to 80 K. It proves that the charged exciton complex in a single quantum dash of the mature InP-based material system can act as a true single photon source up to at least liquid nitrogen temperature. This demonstrates the huge potential of InAs on InP nanostructures as the non-classical light emitters for long-distance fiber-based secure communication technologies.

  1. Photocurrent spectrum study of a quantum dot single-photon detector based on resonant tunneling effect with near-infrared response

    SciTech Connect

    Weng, Q. C.; An, Z. H. E-mail: luwei@mail.sitp.ac.cn; Xiong, D. Y.; Zhu, Z. Q.; Zhang, B.; Chen, P. P.; Li, T. X.; Lu, W. E-mail: luwei@mail.sitp.ac.cn

    2014-07-21

    We present the photocurrent spectrum study of a quantum dot (QD) single-photon detector using a reset technique which eliminates the QD's “memory effect.” By applying a proper reset frequency and keeping the detector in linear-response region, the detector's responses to different monochromatic light are resolved which reflects different detection efficiencies. We find the reset photocurrent tails up to 1.3 μm wavelength and near-infrared (∼1100 nm) single-photon sensitivity is demonstrated due to interband transition of electrons in QDs, indicating the device a promising candidate both in quantum information applications and highly sensitive imaging applications operating in relative high temperatures (>80 K).

  2. Phonon-assisted control of the single-photon spectral characteristics in a semiconductor quantum dot using a single laser pulse

    NASA Astrophysics Data System (ADS)

    Kumar, Parvendra; Vedeshwar, Agnikumar G.

    2017-09-01

    We theoretically demonstrate the phonon-assisted control of the single-photon spectral characteristics such as central frequency and linewidth in a semiconductor quantum dot coupled to a pillar microcavity using a single laser pulse as both excitation and control. We derive the relevant optical Bloch equations from the suitable polaron master equation for taking into account the effects of phonons accurately. We show that with the appropriately chosen parameters of the exciting laser pulse (pump pulse) and cavity, the central frequency and linewidth of the single photon can be controlled simply by controlling the frequency and pulse width of the exciting laser pulse, respectively. Subsequently, we show that these are essentially the phonon-induced processes which ensure that the probability of single-photon emission does not change significantly with the variation of the frequency and pulse width of the exciting laser pulse. Furthermore, we demonstrate that the polarization of the single photon can also be controlled by adjusting the polarization of the pump pulse.

  3. Ramsey Interference with Single Photons

    NASA Astrophysics Data System (ADS)

    Clemmen, Stéphane; Farsi, Alessandro; Ramelow, Sven; Gaeta, Alexander L.

    2016-11-01

    Interferometry using discrete energy levels of nuclear, atomic, or molecular systems is the foundation for a wide range of physical phenomena and enables powerful techniques such as nuclear magnetic resonance, electron spin resonance, Ramsey-based spectroscopy, and laser or maser technology. It also plays a unique role in quantum information processing as qubits may be implemented as energy superposition states of simple quantum systems. Here, we demonstrate quantum interference involving energy states of single quanta of light. In full analogy to the energy levels of atoms or nuclear spins, we implement a Ramsey interferometer with single photons. We experimentally generate energy superposition states of a single photon and manipulate them with unitary transformations to realize arbitrary projective measurements. Our approach opens the path for frequency-encoded photonic qubits in quantum information processing and quantum communication.

  4. Integrated optomechanical single-photon frequency shifter

    NASA Astrophysics Data System (ADS)

    Fan, Linran; Zou, Chang-Ling; Poot, Menno; Cheng, Risheng; Guo, Xiang; Han, Xu; Tang, Hong X.

    2016-12-01

    The ability to manipulate single photons is of critical importance for fundamental quantum optics studies and practical implementations of quantum communications. While extraordinary progresses have been made in controlling spatial, temporal, spin and orbit angular momentum degrees of freedom, frequency-domain control of single photons so far relies on nonlinear optical effects, which have faced obstacles such as noise photons, narrow bandwidth and demanding optical filtering. Here, we demonstrate the first integrated optomechanical single-photon frequency shifter with near-unity efficiency. A frequency shift up to 150 GHz at telecom wavelength is realized without measurable added noise and the preservation of quantum coherence is verified through quantum interference between twin photons of different colours. This single-photon frequency shifter will be invaluable for increasing the channel capacity of quantum communications and compensating frequency mismatch between quantum systems, paving the road towards a hybrid quantum network.

  5. Single-photon decision maker

    PubMed Central

    Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    2015-01-01

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions. PMID:26278007

  6. Single-photon decision maker

    NASA Astrophysics Data System (ADS)

    Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    2015-08-01

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions.

  7. Single-photon decision maker.

    PubMed

    Naruse, Makoto; Berthel, Martin; Drezet, Aurélien; Huant, Serge; Aono, Masashi; Hori, Hirokazu; Kim, Song-Ju

    2015-08-17

    Decision making is critical in our daily lives and for society in general and is finding evermore practical applications in information and communication technologies. Herein, we demonstrate experimentally that single photons can be used to make decisions in uncertain, dynamically changing environments. Using a nitrogen-vacancy in a nanodiamond as a single-photon source, we demonstrate the decision-making capability by solving the multi-armed bandit problem. This capability is directly and immediately associated with single-photon detection in the proposed architecture, leading to adequate and adaptive autonomous decision making. This study makes it possible to create systems that benefit from the quantum nature of light to perform practical and vital intelligent functions.

  8. Quantum interference in a four-level system of a {sup 87}Rb atom: Effects of spontaneously generated coherence

    SciTech Connect

    Wang Dongsheng; Zheng Yujun

    2011-01-15

    In this work, the effects of quantum interference and spontaneously generated coherence (SGC) are theoretically analyzed in a four-level system of a {sup 87}Rb atom. For the effects of SGC, we find that a new kind of electromagnetically induced transparency channel can be induced due to destructive interference, and the nonlinear Kerr absorption can be coherently narrowed or eliminated under different strengths of the coupling and switching fields.

  9. Control of Four-Level Quantum Coherence via Discrete Spectral Shaping of an Optical Frequency Comb

    SciTech Connect

    Stowe, Matthew C.; Peer, Avi; Ye Jun

    2008-05-23

    We present experiments demonstrating high-resolution and wide-bandwidth coherent control of a four-level atomic system in a diamond configuration. A femtosecond frequency comb is used to excite a specific pair of two-photon transitions in cold {sup 87}Rb. The optical-phase-sensitive response of the closed-loop diamond system is studied by controlling the phase of the comb modes with a pulse shaper. Finally, the pulse shape is optimized resulting in a 256% increase in the two-photon transition rate by forcing constructive interference between the mode pairs detuned from an intermediate resonance.

  10. Influence of electron-phonon scattering for an on-demand quantum dot single-photon source using cavity-assisted adiabatic passage

    NASA Astrophysics Data System (ADS)

    Gustin, Chris; Hughes, Stephen

    2017-08-01

    We study the role of electron-phonon scattering for a pulse-triggered quantum dot single-photon source which utilizes a modified version of stimulated Raman adiabatic passage and cavity coupling. This on-demand source is coherently pumped with an optical pulse in the presence of a continuous-wave laser drive, allowing for efficient generation of indistinguishable single photons with polarizations orthogonal to the applied fields. In contrast to previous studies, we explore the role of electron-phonon scattering on this semiconductor system by using a polaron master equation approach to model the biexciton-exciton cascade and cavity mode coupling. In addition to background zero-phonon-line decoherence processes, microscopic electron-acoustic-phonon coupling, which usually degrades the indistinguishability and efficiency of semiconductor photon sources, is rigorously taken into account. We study how different system parameters (including cavity and laser detunings, cavity spectral width, temperature) affect the device performance and contrast the relative influence of intrinsic phonon coupling with other dephasing mechanisms. We describe how this biexciton-exciton cascade scheme allows for true single photons to be generated with over 90% quantum indistinguishability and efficiency simultaneously using realistic experimental parameters. We also show how the double-field dressing can be probed through the cavity-emitted spectrum.

  11. Single-photon property characterization of 1.3 μm emissions from InAs/GaAs quantum dots using silicon avalanche photodiodes

    PubMed Central

    Zhou, P. Y.; Dou, X. M.; Wu, X. F.; Ding, K.; Li, M. F.; Ni, H. Q.; Niu, Z. C.; Jiang, D. S.; Sun, B. Q.

    2014-01-01

    We developed a new approach to test the single-photon emissions of semiconductor quantum dots (QDs) in the optical communication band. A diamond-anvil cell pressure device was used for blue-shifting the 1.3 μm emissions of InAs/GaAs QDs to 0.9 μm for detection by silicon avalanche photodiodes. The obtained g(2)(0) values from the second-order autocorrelation function measurements of several QD emissions at 6.58 GPa were less than 0.3, indicating that this approach provides a convenient and efficient method of characterizing 1.3 μm single-photon source based on semiconductor materials. PMID:24407193

  12. Single-photon property characterization of 1.3 μm emissions from InAs/GaAs quantum dots using silicon avalanche photodiodes.

    PubMed

    Zhou, P Y; Dou, X M; Wu, X F; Ding, K; Li, M F; Ni, H Q; Niu, Z C; Jiang, D S; Sun, B Q

    2014-01-10

    We developed a new approach to test the single-photon emissions of semiconductor quantum dots (QDs) in the optical communication band. A diamond-anvil cell pressure device was used for blue-shifting the 1.3 μm emissions of InAs/GaAs QDs to 0.9 μm for detection by silicon avalanche photodiodes. The obtained g((2))(0) values from the second-order autocorrelation function measurements of several QD emissions at 6.58 GPa were less than 0.3, indicating that this approach provides a convenient and efficient method of characterizing 1.3 μm single-photon source based on semiconductor materials.

  13. Structural and optical properties of position-retrievable low-density GaAs droplet epitaxial quantum dots for application to single photon sources with plasmonic optical coupling.

    PubMed

    Lee, Eun-Hye; Song, Jin-Dong; Han, Il-Ki; Chang, Soo-Kyung; Langer, Fabian; Höfling, Sven; Forchel, Alfred; Kamp, Martin; Kim, Jong-Su

    2015-01-01

    The position of a single GaAs quantum dot (QD), which is optically active, grown by low-density droplet epitaxy (DE) (approximately 4 QDs/μm(2)), was directly observed on the surface of a 45-nm-thick Al0.3Ga0.7As capping layer. The thin thickness of AlGaAs capping layer is useful for single photon sources with plasmonic optical coupling. A micro-photoluminescence for GaAs DE QDs has shown exciton/biexciton behavior in the range of 1.654 to 1.657 eV. The direct observation of positions of low-density GaAs DE QDs would be advantageous for mass fabrication of devices that use a single QD, such as single photon sources.

  14. Blue single photon emission up to 200 K from an InGaN quantum dot in AlGaN nanowire

    NASA Astrophysics Data System (ADS)

    Deshpande, Saniya; Das, Ayan; Bhattacharya, Pallab

    2013-04-01

    We demonstrate polarized blue single photon emission up to 200 K from an In0.2Ga0.8N quantum dot in a single Al0.1Ga0.9N nanowire. The InGaN/AlGaN dot-in-nanowire heterostructure was grown on (111) silicon by plasma assisted molecular beam epitaxy. Nanowires dispersed on a silicon substrate show sharp exciton and biexciton transitions in the micro-photoluminescence spectra. Second-order correlation measurements performed under pulsed excitation at the biexciton wavelength confirm single photon emission, with a g(2)(0) of 0.43 at 200 K. The emitted photons have a short radiative lifetime of 0.7 ns and are linearly polarized along the c-axis of the nanowire with a degree of polarization of 78%.

  15. Zeno effect in degree of polarization of a single photon or quantum-state purity of a spin-1/2 system

    NASA Astrophysics Data System (ADS)

    Luis, Alfredo; Gonzalo, Isabel; Porras, Miguel A.

    2013-06-01

    We describe a version of the Zeno effect where the monitored physical property cannot be represented by a standard operator in the system space and the evolution to be prevented by observation is not unitary. This is the case of quantum-state purity of a spin-1/2 system, which is equivalent to the degree of polarization of a single photon. By a suitable embedding of the system (say, a single photon) in an enlarged space of a pair of photons, pure and fully mixed components lead to orthogonal subspaces, with lack of purity becoming equivalent to entanglement. By imposing desirable properties the representation of the system in the enlarged space is unique. We show that the Zeno effect is possible, and experimentally feasible, in the enlarged space. The peculiarity that photons in identical polarization states are involved in pairs to observe the dynamics of each photon allows us to refer it as the self-Zeno effect or Narcissus effect.

  16. Direct evidence of single quantum dot emission from GaN islands formed at threading dislocations using nanoscale cathodoluminescence: A source of single photons in the ultraviolet

    SciTech Connect

    Schmidt, Gordon Berger, Christoph; Veit, Peter; Metzner, Sebastian; Bertram, Frank; Bläsing, Jürgen; Dadgar, Armin; Strittmatter, André; Christen, Jürgen; Callsen, Gordon; Kalinowski, Stefan; Hoffmann, Axel

    2015-06-22

    Intense emission from GaN islands embedded in AlN resulting from GaN/AlN quantum well growth is directly resolved by performing cathodoluminescence spectroscopy in a scanning transmission electron microscope. Line widths down to 440 μeV are measured in a wavelength region between 220 and 310 nm confirming quantum dot like electronic properties in the islands. These quantum dot states can be structurally correlated to islands of slightly enlarged thicknesses of the GaN/AlN quantum well layer preferentially formed in vicinity to dislocations. The quantum dot states exhibit single photon emission in Hanbury Brown-Twiss experiments with a clear antibunching in the second order correlation function at zero time delay.

  17. Linear optical quantum metrology with single photons: Experimental errors, resource counting, and quantum Cramér-Rao bounds

    NASA Astrophysics Data System (ADS)

    Olson, Jonathan P.; Motes, Keith R.; Birchall, Patrick M.; Studer, Nick M.; LaBorde, Margarite; Moulder, Todd; Rohde, Peter P.; Dowling, Jonathan P.

    2017-07-01

    Quantum number-path entanglement is a resource for supersensitive quantum metrology and in particular provides for sub-shot-noise or even Heisenberg-limited sensitivity. However, such number-path entanglement is thought to have been resource intensive to create in the first place, typically requiring either very strong nonlinearities or nondeterministic preparation schemes with feedforward, which are difficult to implement. Recently [K. R. Motes et al., Phys. Rev. Lett. 114, 170802 (2015), 10.1103/PhysRevLett.114.170802], it was shown that number-path entanglement from a BosonSampling inspired interferometer can be used to beat the shot-noise limit. In this paper we compare and contrast different interferometric schemes, discuss resource counting, calculate exact quantum Cramér-Rao bounds, and study details of experimental errors.

  18. Four-level atom dynamics and emission statistics using a quantum jump approach

    NASA Astrophysics Data System (ADS)

    Sandhya, S. N.

    2007-01-01

    Four-level atom dynamics is studied in a ladder system in the nine parameter space consisting of driving field strengths, detunings and decay constants, {Ω1,Ω2,Ω3,Δ1,Δ2,Δ3,Γ2,Γ3,Γ4} . One can selectively excite or induce two-level behavior between particular levels of ones choice by appropriately tuning the driving field strengths at three-photon resonance. The dynamics may be classified into two main regions of interest (i) small Ω2 coupling the ∣2⟩-∣3⟩ transition and (ii) large Ω2 . In case (i) one sees two-level behavior consisting of adjacent levels and in a particular region in the parameter space, there is an intermittent shelving of the electrons in one of the two subsystems. In case (ii) the levels consist of the ground state and the upper most level. Emission statistics is studied using the delay function approach in both the cases. In case (i), the behavior of the second order correlation function g2(t) , is similar to that of two-level emission for low Ω1 coupling the ∣1⟩-∣2⟩ transition, and the correlation increases with Ω1 for smaller time delays. While, in case (ii) when, in addition, Ω3 coupling the ∣3⟩-∣4⟩ transitionis kept low, g2(t) shows superpoissonian distribution, which may be attributed to three-photon processes.

  19. All-Optical Fiber Hanbury Brown & Twiss Interferometer to study 1300 nm single photon emission of a metamorphic InAs Quantum Dot

    NASA Astrophysics Data System (ADS)

    Muñoz-Matutano, G.; Barrera, D.; Fernández-Pousa, C. R.; Chulia-Jordan, R.; Seravalli, L.; Trevisi, G.; Frigeri, P.; Sales, S.; Martínez-Pastor, J.

    2016-06-01

    New optical fiber based spectroscopic tools open the possibility to develop more robust and efficient characterization experiments. Spectral filtering and light reflection have been used to produce compact and versatile fiber based optical cavities and sensors. Moreover, these technologies would be also suitable to study N-photon correlations, where high collection efficiency and frequency tunability is desirable. We demonstrated single photon emission of a single quantum dot emitting at 1300 nm, using a Fiber Bragg Grating for wavelength filtering and InGaAs Avalanche Photodiodes operated in Geiger mode for single photon detection. As we do not observe any significant fine structure splitting for the neutral exciton transition within our spectral resolution (46 μeV), metamorphic QD single photon emission studied with our all-fiber Hanbury Brown & Twiss interferometer could lead to a more efficient analysis of entangled photon sources at telecom wavelength. This all-optical fiber scheme opens the door to new first and second order interferometers to study photon indistinguishability, entangled photon and photon cross correlation in the more interesting telecom wavelengths.

  20. All-Optical Fiber Hanbury Brown &Twiss Interferometer to study 1300 nm single photon emission of a metamorphic InAs Quantum Dot.

    PubMed

    Muñoz-Matutano, G; Barrera, D; Fernández-Pousa, C R; Chulia-Jordan, R; Seravalli, L; Trevisi, G; Frigeri, P; Sales, S; Martínez-Pastor, J

    2016-06-03

    New optical fiber based spectroscopic tools open the possibility to develop more robust and efficient characterization experiments. Spectral filtering and light reflection have been used to produce compact and versatile fiber based optical cavities and sensors. Moreover, these technologies would be also suitable to study N-photon correlations, where high collection efficiency and frequency tunability is desirable. We demonstrated single photon emission of a single quantum dot emitting at 1300 nm, using a Fiber Bragg Grating for wavelength filtering and InGaAs Avalanche Photodiodes operated in Geiger mode for single photon detection. As we do not observe any significant fine structure splitting for the neutral exciton transition within our spectral resolution (46 μeV), metamorphic QD single photon emission studied with our all-fiber Hanbury Brown &Twiss interferometer could lead to a more efficient analysis of entangled photon sources at telecom wavelength. This all-optical fiber scheme opens the door to new first and second order interferometers to study photon indistinguishability, entangled photon and photon cross correlation in the more interesting telecom wavelengths.

  1. All-Optical Fiber Hanbury Brown & Twiss Interferometer to study 1300 nm single photon emission of a metamorphic InAs Quantum Dot

    PubMed Central

    Muñoz-Matutano, G.; Barrera, D.; Fernández-Pousa, C.R.; Chulia-Jordan, R.; Seravalli, L.; Trevisi, G.; Frigeri, P.; Sales, S.; Martínez-Pastor, J.

    2016-01-01

    New optical fiber based spectroscopic tools open the possibility to develop more robust and efficient characterization experiments. Spectral filtering and light reflection have been used to produce compact and versatile fiber based optical cavities and sensors. Moreover, these technologies would be also suitable to study N-photon correlations, where high collection efficiency and frequency tunability is desirable. We demonstrated single photon emission of a single quantum dot emitting at 1300 nm, using a Fiber Bragg Grating for wavelength filtering and InGaAs Avalanche Photodiodes operated in Geiger mode for single photon detection. As we do not observe any significant fine structure splitting for the neutral exciton transition within our spectral resolution (46 μeV), metamorphic QD single photon emission studied with our all-fiber Hanbury Brown & Twiss interferometer could lead to a more efficient analysis of entangled photon sources at telecom wavelength. This all-optical fiber scheme opens the door to new first and second order interferometers to study photon indistinguishability, entangled photon and photon cross correlation in the more interesting telecom wavelengths. PMID:27257122

  2. Influence of incoherent pumping field on spatial evolution of gain without inversion in a four-level quantum dot nanostructure

    NASA Astrophysics Data System (ADS)

    Karimi, R.; Asadpour, S. H.; Batebi, S.; Rahimpour Soleimani, H.

    2015-09-01

    We investigated the propagation effect on gain without inversion (GWI) phenomena in an open four level quantum dot nanostructure in the presence and absence of incoherent pumping field. The simulation results show that, the ratio of the injection rates and strength of incoherent pumping field has remarkable effect on spatial evolution of GWI and output. We can obtain the optimal GWI and output by choosing appropriate values of parameters. The theoretical results show that, in the open system the value of gain (output) in the absence of incoherent pumping field is much larger than that in the presence of incoherent pumping field.

  3. Influence of Fano interference and incoherent processes on optical bistability in a four-level quantum dot nanostructure

    NASA Astrophysics Data System (ADS)

    Seyyed, Hossein Asadpour; G, Solookinejad; M, Panahi; E Ahmadi, Sangachin

    2016-03-01

    Role of Fano interference and incoherent pumping field on optical bistability in a four-level designed InGaN/GaN quantum dot nanostructure embedded in a unidirectional ring cavity are analyzed. It is found that intensity threshold of optical bistability can be manipulated by Fano interference. It is shown that incoherent pumping fields make the threshold of optical bistability behave differently by Fano interference. Moreover, in the presence of Fano interference the medium becomes phase-dependent. Therefore, the relative phase of applied fields can affect the behaviors of optical bistability and intensity threshold can be controlled easily.

  4. Development of the experimental setup for investigation of latching of superconducting single-photon detector caused by blinding attack on the quantum key distribution system

    NASA Astrophysics Data System (ADS)

    Elezov, M. S.; Ozhegov, R. V.; Goltsman, G. N.; Makarov, V.

    2016-12-01

    Recently bright-light control of the SSPD has been demonstrated. This attack employed a "backdoor" in the detector biasing scheme. Under bright-light illumination, SSPD becomes resistive and remains "latched" in the resistive state even when the light is switched off. While the SSPD is latched, Eve can simulate SSPD single-photon response by sending strong light pulses, thus deceiving Bob. We developed the experimental setup for investigation of a dependence on latching threshold of SSPD on optical pulse length and peak power. By knowing latching threshold it is possible to understand essential requirements for development countermeasures against blinding attack on quantum key distribution system with SSPDs.

  5. Information Leakage in Efficient Bidirectional Quantum Secure Direct Communication with Single Photons in Both Polarization and Spatial-Mode Degrees of Freedom

    NASA Astrophysics Data System (ADS)

    Zhang, Cai; Situ, Haozhen

    2016-11-01

    Recently, Wang et al. presented a bidirectional quantum secure direct communication protocol with single photons in both polarization and spatial-mode degrees of freedom (Int. J. Theor. Phys. 54(10): 3443-3453, 2015). They claimed that their protocol was efficient and removed the drawback of information leakage. However, we found that the information leakage actually exists in their protocol. In this paper, we analyze Wang et al.'s protocol in detail. In addition, we propose an improvement to avoid the information leakage. The security of the improved protocol has also been discussed.

  6. Development of the experimental setup for investigation of latching of superconducting single-photon detector caused by blinding attack on the quantum key distribution system

    NASA Astrophysics Data System (ADS)

    Elezov, M. S.; Ozhegov, R. V.; Goltsman, G. N.; Makarov, V.

    2017-01-01

    Recently bright-light control of the SSPD has been demonstrated. This attack employed a "backdoor" in the detector biasing scheme. Under bright-light illumination, SSPD becomes resistive and remains "latched" in the resistive state even when the light is switched off. While the SSPD is latched, Eve can simulate SSPD single-photon response by sending strong light pulses, thus deceiving Bob. We developed the experimental setup for investigation of a dependence on latching threshold of SSPD on optical pulse length and peak power. By knowing latching threshold it is possible to understand essential requirements for development countermeasures against blinding attack on quantum key distribution system with SSPDs.

  7. Dynamic Multi-Party Quantum Private Comparison Protocol with Single Photons in Both Polarization and Spatial-Mode Degrees of Freedom

    NASA Astrophysics Data System (ADS)

    Liu, Wen; Wang, Yong-Bin

    2016-12-01

    A dynamic quantum private comparison protocol based on the single photons in both polarization and spatial-mode degrees of freedom is proposed. In this protocol, any two parties of n( n ≥ 4) parties can compare their private information with the help of others n - 2 parties. And any party can join in the protocol to take part in the comparison of n parties. Correctness analysis shows that the proposed protocol can be used to compare their information correctly. Security analysis shows that the proposed protocol can resist the general active attacks from an outside eavesdropper. And it can overcomes the problem of information leakage.

  8. Enhanced generation of twin single-photon states via quantum interference in parametric down-conversion: Application to two-photon quantum photolithography

    SciTech Connect

    Gerry, Christopher C.

    2003-04-01

    Two-photon interferometric quantum photon lithography for light of wavelength {lambda} is capable of beating the Rayleigh diffraction limit of resolution {lambda}/4 to the level of {lambda}/8. The required twin single-photon states |1>{sub a}|1>{sub b}, which are converted into maximally entangled states by a 50:50 beam splitter, can be generated from a nondegenerate parametric amplifier initially in vacuum states and with a weak pump field. Increasing the pump strength can slightly increase the production rate of the desired state and it will also increase the production of the twin two-photon states |2>{sub a}|2>{sub b}, which leads to an unwanted background term. In this paper we show that, assuming a weak pair coherent state as input to the amplifier, quantum interference can be used to quench the production of the |2>{sub a}|2>{sub b} state and to enhance the production of the |1>{sub a}|1>{sub b} state by almost sixfold.

  9. Stroing single-photons in microcavities arrays

    NASA Astrophysics Data System (ADS)

    Mirza, Imran M.; Enk, S. J. Van; Kimble, H. J.

    2014-03-01

    Coupling light to arrays of microcavities is one of the most promising avenues to store/delay classical light pulses [F. Krauss, Nat. Phot. 2, 448-450 (2008)]. However, from the perspective of benefiting quantum communication protocols, the same ideas in principle can be extended down to the single-photon (quantum) level as well. Particularly, for the purposes of entanglement purification and quantum repeaters a reliable storage of single photons is needed. We consider in our work [I. M. Mirza, S. Van Enk, H. Kimble JOSA B, 30,10 (2013)] cavities that are coupled through an optical fiber which is assumed to be forming a Markovian bath. For this study two powerful open quantum system techniques, Input-Output theory for cascaded quantum systems and the Quantum Trajectory approach are used in combination. For the confirmation of photon delays the Time-Dependent Spectrum of such a single photon is obtained. Interestingly this leads to a hole-burning effect showing that only certain frequency components in the single photon wavepackets are stored inside the cavities and hence are delayed in time. Since on-demand production of single photons is not an easy task we include in our description the actual generation of the single photon by assuming a single emitter in one the resonators.

  10. Single-photon detection and its applications

    NASA Astrophysics Data System (ADS)

    Liang, Yan; Zeng, HePing

    2014-07-01

    A single-photon detector is an extremely sensitive device capable of registering photons, offering essential technical support for optics quantum information applications. We review herein our recent experimental progress in the development and application of single-photon detection techniques. Techniques based on advanced self-differencing, low-pass filtering, frequency up-conversion and photon-number-resolving are introduced for attaining high-speed, high-efficiency, low-noise single-photon detection at infrared wavelengths. The advantages of high-speed single-photon detection are discussed in some applications, such as the laser ranging and quantum key distribution. The photon-number-resolving detection is shown to support efficient quantum random number generation.

  11. Mesa-top quantum dot single photon emitter arrays: Growth, optical characteristics, and the simulated optical response of integrated dielectric nanoantenna-waveguide systems

    NASA Astrophysics Data System (ADS)

    Zhang, Jiefei; Chattaraj, Swarnabha; Lu, Siyuan; Madhukar, Anupam

    2016-12-01

    Nanophotonic quantum information processing systems require spatially ordered, spectrally uniform single photon sources (SPSs) integrated on-chip with co-designed light manipulating elements providing emission rate enhancement, emitted photon guidance, and lossless propagation. Towards this goal, we consider systems comprising an SPS array with each SPS coupled to a dielectric building block (DBB) based multifunctional light manipulation unit (LMU). For the SPS array, we report triggered single photon emission from GaAs(001)/InGaAs single quantum dots grown selectively on top of nanomesas using the approach of substrate-encoded size-reducing epitaxy (SESRE). Systematic temperature and power dependent photoluminescence (PL), PL excitation, time-resolved PL, and emission statistics studies reveal high spectral uniformity and single photon emission at 8 K with g(2)(0) of 0.19 ± 0.03. The SESRE based SPS arrays, following growth of a planarizing overlayer, are readily integrable with LMUs fabricated subsequently using either the 2D photonic crystal approach or, as theoretically examined here, DBB based LMUs. We report the simulated optical response of SPS embedded in DBB based nanoantenna-waveguide structures as the multifunctional LMU. The multiple functions of emission rate enhancement, guiding, and lossless propagation are derived from the behavior of the same collective Mie resonance (dominantly magnetic) of the interacting DBB based LMU tuned to the SPS targeted emission wavelength of 980 nm. The simulation utilizes an analytical approach that provides physical insight into the obtained numerical results. Together, the combined experimental and modelling demonstrations open a rich approach to implementing co-designed on-chip integrated SPS-LMUs that, in turn, serve as basic elements of integrated nanophotonic information processing systems.

  12. What are single photons good for?

    NASA Astrophysics Data System (ADS)

    Sangouard, Nicolas; Zbinden, Hugo

    2012-10-01

    In a long-held preconception, photons play a central role in present-day quantum technologies. But what are sources producing photons one by one good for precisely? Well, in opposition to what many suggest, we show that single-photon sources are not helpful for point to point quantum key distribution because faint laser pulses do the job comfortably. However, there is no doubt about the usefulness of sources producing single photons for future quantum technologies. In particular, we show how single-photon sources could become the seed of a revolution in the framework of quantum communication, making the security of quantum key distribution device-independent or extending quantum communication over many hundreds of kilometers. Hopefully, these promising applications will provide a guideline for researchers to develop more and more efficient sources, producing narrowband, pure and indistinguishable photons at appropriate wavelengths.

  13. InGaAsP/InP Micropillar Cavities for 1.55 μm Quantum-Dot Single Photon Sources

    NASA Astrophysics Data System (ADS)

    Xie, Xiumin; Xu, Qiang; Shen, Bizhou; Chen, Jian; Dai, Qian; Shi, Zhu; Yu, Libo; Wang, Zhiming M.; Song, Hai-Zhi

    2017-06-01

    Micropillar cavities containing 1.55 μm quantum dots are required for silica-fiber based quantum information processing. The straight way is to construct micropillars consisting of InGaAsP/InP distributed Bragg reflectors. We perform a systematic study mainly on optical properties correlated to the micropillar diameter. As expected, the mode wavelength increases with extending micropillar diameter and tends to saturate at 1.55 μm for the diameter larger than 2.0 μm. Able to be as high as 104, the quality factor, however, is almost independent of pillar diameter, which may be the result of the small refractive index contrast. The Purcell factor reaches highest ( >130) at pillar diameter of ∼0.6 μm, suggesting that these cavities could serve as efficient 1.55 μm single photon sources. The output efficiency increases with extending diameter, and is acceptably good at small diameters. Although not easy in fabrication technique, this cavity provides monolithic scheme for constructing 1.55 μm single photon sources.

  14. Bright single photons for light-matter interaction

    NASA Astrophysics Data System (ADS)

    Wu, Chih-Hsiang; Wu, Tsung-Yao; Yeh, Yung-Chin; Liu, Po-Hui; Chang, Chin-Hsuan; Liu, Chiao-Kai; Cheng, Ting; Chuu, Chih-Sung

    2017-08-01

    Single photons of subnatural linewidth and high spectral brightness are necessary for efficient light-matter interaction at the single-photon level, which lies at the heart of many quantum photonic technologies. Here we demonstrate a bright source of single photons with subnatural linewidth, controllable waveforms, and a high spectral brightness of 3.67 ×105 s -1mW -1MHz -1. The interaction between the single photons and atoms is demonstrated by the controlled absorption of the single photons in an atomic vapor. Our work has potential applications in quantum information technologies.

  15. Single photon emission at 1.55 μm from charged and neutral exciton confined in a single quantum dash

    SciTech Connect

    Dusanowski, Ł. Syperek, M.; Mrowiński, P.; Rudno-Rudziński, W.; Misiewicz, J.; Sęk, G.; Somers, A.; Kamp, M.; Höfling, S.; Reithmaier, J. P.

    2014-07-14

    We investigate charged and neutral exciton complexes confined in a single self-assembled InAs/InGaAlAs/InP quantum dash emitting at 1.55 μm. The emission characteristics have been probed by measuring high-spatial-resolution polarization-resolved photoluminescence and cross-correlations of photon emission statistics at T = 5 K. The photon auto-correlation histogram of the emission from both the neutral and charged exciton indicates a clear antibunching dip with as-measured g{sup (2)}(0) values of 0.18 and 0.31, respectively. It proves that these exciton complexes confined in single quantum dashes of InP-based material system can act as true single photon emitters being compatible with standard long-distance fiber communication technology.

  16. Enhanced single photon emission from positioned InP/GaInP quantum dots coupled to a confined Tamm-plasmon mode

    SciTech Connect

    Braun, T.; Baumann, V.; Iff, O.; Schneider, C.; Kamp, M.; Höfling, S.

    2015-01-26

    We report on the enhancement of the spontaneous emission in the visible red spectral range from site-controlled InP/GaInP quantum dots by resonant coupling to Tamm-plasmon modes confined beneath gold disks in a hybrid metal/semiconductor structure. The enhancement of the emission intensity is confirmed by spatially resolved micro-photoluminescence area scans and temperature dependent measurements. Single photon emission from our coupled system is verified via second order autocorrelation measurements. We observe bright single quantum dot emission of up to ∼173 000 detected photons per second at a repetition rate of the excitation source of 82 MHz, and calculate an extraction efficiency of our device as high as 7%.

  17. Time-resolved photoluminescence measurements of InGaAs/ InP multiple-quantum-well structures at 1.3-µm wavelengths by use of germanium single-photon avalanche photodiodes.

    PubMed

    Buller, G S; Fancey, S J; Massa, J S; Walker, A C; Cova, S; Lacaita, A

    1996-02-20

    A commercially available germanium avalanche photodiode operating in the single-photon-counting mode has been used to perform time-resolved photoluminescence measurements on InGaAs/lnP multiple-quantum-well structures. Photoluminescence in the spectral region of 1.3-1.48 µm was detected with picosecond timing accuracy by use of the time-correlated single-photon counting technique. The carrier dynamics were monitored for excess photogenerated carrier densities in the range 10(18)-10(15) cm(-3). The recombination time is compared for similar InGaAs-based quantum-well structures grown by use of different epitaxial processes.

  18. Single-photon emission at a rate of 143 MHz from a deterministic quantum-dot microlens triggered by a mode-locked vertical-external-cavity surface-emitting laser

    SciTech Connect

    Schlehahn, A.; Gschrey, M.; Schnauber, P.; Schulze, J.-H.; Rodt, S.; Strittmatter, A.; Heindel, T. Reitzenstein, S.; Gaafar, M.; Vaupel, M.; Stolz, W.; Rahimi-Iman, A.; Koch, M.

    2015-07-27

    We report on the realization of a quantum dot (QD) based single-photon source with a record-high single-photon emission rate. The quantum light source consists of an InGaAs QD which is deterministically integrated within a monolithic microlens with a distributed Bragg reflector as back-side mirror, which is triggered using the frequency-doubled emission of a mode-locked vertical-external-cavity surface-emitting laser (ML-VECSEL). The utilized compact and stable laser system allows us to excite the single-QD microlens at a wavelength of 508 nm with a pulse repetition rate close to 500 MHz at a pulse width of 4.2 ps. Probing the photon statistics of the emission from a single QD state at saturation, we demonstrate single-photon emission of the QD-microlens chip with g{sup (2)}(0) < 0.03 at a record-high single-photon flux of (143 ± 16) MHz collected by the first lens of the detection system. Our approach is fully compatible with resonant excitation schemes using wavelength tunable ML-VECSELs, which will optimize the quantum optical properties of the single-photon emission in terms of photon indistinguishability.

  19. Single-photon emission at a rate of 143 MHz from a deterministic quantum-dot microlens triggered by a mode-locked vertical-external-cavity surface-emitting laser

    NASA Astrophysics Data System (ADS)

    Schlehahn, A.; Gaafar, M.; Vaupel, M.; Gschrey, M.; Schnauber, P.; Schulze, J.-H.; Rodt, S.; Strittmatter, A.; Stolz, W.; Rahimi-Iman, A.; Heindel, T.; Koch, M.; Reitzenstein, S.

    2015-07-01

    We report on the realization of a quantum dot (QD) based single-photon source with a record-high single-photon emission rate. The quantum light source consists of an InGaAs QD which is deterministically integrated within a monolithic microlens with a distributed Bragg reflector as back-side mirror, which is triggered using the frequency-doubled emission of a mode-locked vertical-external-cavity surface-emitting laser (ML-VECSEL). The utilized compact and stable laser system allows us to excite the single-QD microlens at a wavelength of 508 nm with a pulse repetition rate close to 500 MHz at a pulse width of 4.2 ps. Probing the photon statistics of the emission from a single QD state at saturation, we demonstrate single-photon emission of the QD-microlens chip with g(2)(0) < 0.03 at a record-high single-photon flux of (143 ± 16) MHz collected by the first lens of the detection system. Our approach is fully compatible with resonant excitation schemes using wavelength tunable ML-VECSELs, which will optimize the quantum optical properties of the single-photon emission in terms of photon indistinguishability.

  20. Limitation of decoy-state Scarani-Acin-Ribordy-Gisin quantum-key-distribution protocols with a heralded single-photon source

    SciTech Connect

    Zhang Shengli; Zou Xubo; Li Ke; Guo Guangcan; Jin Chenhui

    2007-10-15

    For the Bennett-Brassard 1984 (BB84) quantum key distribution, longer distance and higher key generating rate is shown with a heralded single-photon source (HSPS) [Phys. Rev. A. 73, 032331 (2006)]. In this paper, the performance of the Scarani-Acin-Ribordy-Gisim (SARG) protocol utilizing the HSPS sources is considered and the numerical simulation turns out that still a significant improvement in secret key generating rate can also be observed. It is shown that the security distance for HSPS+SARG is 120 km. However, compared with the HSPS+BB84 protocols, the HSPS+SARG protocol has a lower secret key rate and a shorter distance. Thus we show the HSPS+BB84 implementation is a preferable protocol for long distance transmittance.

  1. Single-photon detection, truth, and misinterpretation

    NASA Astrophysics Data System (ADS)

    Berloffa, E. H.

    2013-10-01

    Within this investigation it is critically questioned, if we really can detect "single photons", respectively the response of a single quantum transition by use of modern photon detectors. In the course it is shown that avalanche photodiodes (AVDs) especially in the "Geiger" mode by virtue of its geometry (effective area) indeed can detect "single photon" events as proclaimed by the manufacturers, but they tacitly assume the bandwidth of originating visible source being not greater than ~ 2.107 [Hz]. A short excurse to solid state basic physics makes it obvious applying the adequate doping accomplishes "single photon detection". Nevertheless this does not mean there is a 1:1 correspondence between a photon emanated from the source location and that detected within the detector module. Propagation characteristics were simply overlooked during the numerous discussions about "single photon" detection. Practical examples are worked out on hand of a pin- / and a AVDphotodiode.

  2. Simulating single photons with realistic photon sources

    NASA Astrophysics Data System (ADS)

    Yuan, Xiao; Zhang, Zhen; Lütkenhaus, Norbert; Ma, Xiongfeng

    2016-12-01

    Quantum information processing provides remarkable advantages over its classical counterpart. Quantum optical systems have been proved to be sufficient for realizing general quantum tasks, which, however, often rely on single-photon sources. In practice, imperfect single-photon sources, such as a weak-coherent-state source, are used instead, which will inevitably limit the power in demonstrating quantum effects. For instance, with imperfect photon sources, the key rate of the Bennett-Brassard 1984 (BB84) quantum key distribution protocol will be very low, which fortunately can be resolved by utilizing the decoy-state method. As a generalization, we investigate an efficient way to simulate single photons with imperfect ones to an arbitrary desired accuracy when the number of photonic inputs is small. Based on this simulator, we can thus replace the tasks that involve only a few single-photon inputs with the ones that make use of only imperfect photon sources. In addition, our method also provides a quantum simulator to quantum computation based on quantum optics. In the main context, we take a phase-randomized coherent state as an example for analysis. A general photon source applies similarly and may provide some further advantages for certain tasks.

  3. Solid-state single-photon emitters

    NASA Astrophysics Data System (ADS)

    Aharonovich, Igor; Englund, Dirk; Toth, Milos

    2016-10-01

    Single-photon emitters play an important role in many leading quantum technologies. There is still no 'ideal' on-demand single-photon emitter, but a plethora of promising material systems have been developed, and several have transitioned from proof-of-concept to engineering efforts with steadily improving performance. Here, we review recent progress in the race towards true single-photon emitters required for a range of quantum information processing applications. We focus on solid-state systems including quantum dots, defects in solids, two-dimensional hosts and carbon nanotubes, as these are well positioned to benefit from recent breakthroughs in nanofabrication and materials growth techniques. We consider the main challenges and key advantages of each platform, with a focus on scalable on-chip integration and fabrication of identical sources on photonic circuits.

  4. Micro-Photoluminescence Characterization of Low Density Droplet GaAs Quantum Dots for Single Photon Sources

    SciTech Connect

    Ha, S.-K.; Song, J. D.; Lim, J. Y.; Choi, W. J.; Han, I. K.; Lee, J. I.; Bounouar, S.; Donatini, F.; Dang, L. S.; Poizat, J. P.

    2011-12-23

    The GaAs quantum dots in AlGaAs barriers were grown by droplet epitaxy, emitting around 700 nm in wavelength which is compatible with low cost Si based detectors. The excitation power dependent and time resolved micro-photoluminescence measurements identified optical characteristics of exciton and biexciton states which are attributed to good quantum confinements in GaAs QDs.

  5. Spectral compression of single-photon-level laser pulse

    PubMed Central

    Li, Yuanhua; Xiang, Tong; Nie, Yiyou; Sang, Minghuang; Chen, Xianfeng

    2017-01-01

    We experimentally demonstrate that the bandwidth of single photons laser pulse is compressed by a factor of 58 in a periodically poled lithium niobate (PPLN) waveguide chip. A positively chirped single photons laser pulse and a negatively chirped classical laser pulse are employed to produce a narrowband single photon pulse with new frequency through sum-frequency generation. In our experiment, the frequency and bandwidth of single photons at 1550 nm are simultaneously converted. Our results mark a critical step towards the realization of coherent photonic interface between quantum communication at 1550 nm and quantum memory in the near-visible window. PMID:28240245

  6. Spectral compression of single-photon-level laser pulse

    NASA Astrophysics Data System (ADS)

    Li, Yuanhua; Xiang, Tong; Nie, Yiyou; Sang, Minghuang; Chen, Xianfeng

    2017-02-01

    We experimentally demonstrate that the bandwidth of single photons laser pulse is compressed by a factor of 58 in a periodically poled lithium niobate (PPLN) waveguide chip. A positively chirped single photons laser pulse and a negatively chirped classical laser pulse are employed to produce a narrowband single photon pulse with new frequency through sum-frequency generation. In our experiment, the frequency and bandwidth of single photons at 1550 nm are simultaneously converted. Our results mark a critical step towards the realization of coherent photonic interface between quantum communication at 1550 nm and quantum memory in the near-visible window.

  7. Ultrafast time measurements by time-correlated single photon counting coupled with superconducting single photon detector

    SciTech Connect

    Shcheslavskiy, V. Becker, W.; Morozov, P.; Divochiy, A.

    2016-05-15

    Time resolution is one of the main characteristics of the single photon detectors besides quantum efficiency and dark count rate. We demonstrate here an ultrafast time-correlated single photon counting (TCSPC) setup consisting of a newly developed single photon counting board SPC-150NX and a superconducting NbN single photon detector with a sensitive area of 7 × 7 μm. The combination delivers a record instrument response function with a full width at half maximum of 17.8 ps and system quantum efficiency ∼15% at wavelength of 1560 nm. A calculation of the root mean square value of the timing jitter for channels with counts more than 1% of the peak value yielded about 7.6 ps. The setup has also good timing stability of the detector–TCSPC board.

  8. Single photon emission based on coherent state preparation

    NASA Astrophysics Data System (ADS)

    Ester, P.; Lackmann, L.; Michaelis de Vasconcellos, S.; Hübner, M. C.; Zrenner, A.; Bichler, M.

    2007-09-01

    The authors report here on deterministic single photon emission after coherent optical state preparation in the p-shell of a single InGaAs /GaAs quantum dot. In the approach, they use p-shell Rabi flopping followed by relaxation to the s-shell ground state with subsequent spontaneous single photon emission. Pulsed photon correlation experiments show complete suppression of the correlation peak at zero time delay and hence demonstrate clean single photon emission.

  9. Quantum logic gates based on off-resonant cavity-assisted interaction between three-level atoms and single photons

    NASA Astrophysics Data System (ADS)

    Akbari, M.; Andrianov, S. N.; Kalachev, A. A.

    2017-07-01

    A scheme for implementing quantum gates on the basis of a hybrid system that consists of flying photons and a stationary three-level atom interacting with each other in a microring resonator is developed. By employing the Schrieffer-Wolf transformation, it is shown that various two-qubit gates can be implemented under conditions of dispersive interaction without the need for orthogonal Λ structure of optical transitions. As a promising system for implementation, NV centers are considered.

  10. Controlling of group velocity via terahertz signal radiation in a defect medium doped by four-level InGaN/GaN quantum dot nanostructure

    NASA Astrophysics Data System (ADS)

    Jafarzadeh, Hossein; Sangachin, Elnaz Ahmadi; Asadpour, Seyyed Hossein

    2015-07-01

    In this paper, we propose a novel scheme for controlling the group velocity of transmitted and reflected pulse from defect medium doped with four-level InGaN/GaN quantum dot nanostructure. Quantum dot nanostructure is designed numerically by Schrödinger and Poisson equations which solve self consistently. By size control of quantum dot and external voltage, one can design a four-level quantum dot with appropriate energy levels which can be suitable for controlling the group velocity of pulse transmission and reflection from defect slab with terahertz signal field. It is found that in the presence and absence of terahertz signal field the behaviors of transmission and reflection pulses are completely different. Moreover, it is shown that for strong terahertz signal field, by changing the thickness of the slab, simultaneous peak and dip for transmission and reflection pulse are obtained.

  11. Single-photon space-like antibunching

    NASA Astrophysics Data System (ADS)

    Guerreiro, Thiago; Sanguinetti, Bruno; Zbinden, Hugo; Gisin, Nicolas; Suarez, Antoine

    2012-06-01

    We use heralded single photons to perform an antibunching experiment in which the clicks at the detectors are space-like separated events. The idea of such experiment dates back to the 5th Solvay conference, when it was proposed by Einstein as an expression of his concerns about quantum theory.

  12. Interactive Screen Experiments with Single Photons

    ERIC Educational Resources Information Center

    Bronner, Patrick; Strunz, Andreas; Silberhorn, Christine; Meyn, Jan-Peter

    2009-01-01

    Single photons are used for fundamental quantum physics experiments as well as for applications. Originally being a topic of advance courses, such experiments are increasingly a subject of undergraduate courses. We provide interactive screen experiments (ISE) for supporting the work in a real laboratory, and for students who do not have access to…

  13. Interactive Screen Experiments with Single Photons

    ERIC Educational Resources Information Center

    Bronner, Patrick; Strunz, Andreas; Silberhorn, Christine; Meyn, Jan-Peter

    2009-01-01

    Single photons are used for fundamental quantum physics experiments as well as for applications. Originally being a topic of advance courses, such experiments are increasingly a subject of undergraduate courses. We provide interactive screen experiments (ISE) for supporting the work in a real laboratory, and for students who do not have access to…

  14. Schemes for quantum key distribution with higher-order alphabets using single-photon fractional Fourier optics

    NASA Astrophysics Data System (ADS)

    Walborn, S. P.; Lemelle, D. S.; Tasca, D. S.; Souto Ribeiro, P. H.

    2008-06-01

    We propose generalized quantum key distribution schemes using spatially encoded d -dimensional qudits based on fractional Fourier transform operations. We determine the necessary conditions on the orders of the transforms which ensure a shared secret random key string and briefly discuss the transmission rate and a possible encoding procedure. We also show that the fractional Fourier transform can be used to analyze more general eavesdropping strategies, including an intermediate-basis attack. The error rate and information gain for the intercept-resend and intermediate-basis attacks are briefly analyzed for a particular example. Effects of atmospheric turbulence in a free-space transmission are considered.

  15. Fabrication of InAs quantum dots in AlAs/GaAs DBR pillar microcavities for single photon sources

    SciTech Connect

    Zhang Bingyang; Solomon, Glenn S.; Pelton, Matthew; Plant, Jocelyn; Santori, Charles; Vuckovic, Jelena; Yamamoto, Yoshihisa

    2005-04-01

    We report the molecular beam epitaxy growth of low-density strain-induced InAs quantum dots (QD) embedded in an AlAs/GaAs distributed Bragg reflector structure for a triggered photon source. By optimal selection of growth temperature, InAs deposited thickness and other experimental parameters, it is possible to grow low density (10/{mu}m{sup 2}) InAs quantum dots with a suitable emission wavelength for a triggered photon source. The empirical formulas for the refractive indices of AlAs and GaAs materials at high temperature over a wide wavelength range are constructed by combining high resolution x-ray diffraction, dynamic optical reflectivity, and optical reflectivity spectrum techniques. Utilizing the electron-beam lithography and electron-cyclotron-resonance plasma etching techniques, a micropost microcavity with the top diameter of 0.6 {mu}m and the post height of 4.2 {mu}m has been fabricated. Narrow, spectrally limited single QD emission embedded in a micropost microcavity is observed in the photoluminescence.

  16. Design considerations of high-performance InGaAs/InP single-photon avalanche diodes for quantum key distribution.

    PubMed

    Ma, Jian; Bai, Bing; Wang, Liu-Jun; Tong, Cun-Zhu; Jin, Ge; Zhang, Jun; Pan, Jian-Wei

    2016-09-20

    InGaAs/InP single-photon avalanche diodes (SPADs) are widely used in practical applications requiring near-infrared photon counting such as quantum key distribution (QKD). Photon detection efficiency and dark count rate are the intrinsic parameters of InGaAs/InP SPADs, due to the fact that their performances cannot be improved using different quenching electronics given the same operation conditions. After modeling these parameters and developing a simulation platform for InGaAs/InP SPADs, we investigate the semiconductor structure design and optimization. The parameters of photon detection efficiency and dark count rate highly depend on the variables of absorption layer thickness, multiplication layer thickness, excess bias voltage, and temperature. By evaluating the decoy-state QKD performance, the variables for SPAD design and operation can be globally optimized. Such optimization from the perspective of specific applications can provide an effective approach to design high-performance InGaAs/InP SPADs.

  17. Quantum and thermal phase slips in superconducting niobium nitride (NbN) ultrathin crystalline nanowire: application to single photon detection.

    PubMed

    Delacour, Cécile; Pannetier, Bernard; Villegier, Jean-Claude; Bouchiat, Vincent

    2012-07-11

    We present low-temperature electronic transport properties of superconducting nanowires obtained by nanolithography of 4-nm-thick niobium nitride (NbN) films epitaxially grown on sapphire substrate. Below 6 K, clear evidence of phase slippages is observed in the transport measurements. Upon lowering the temperature, we observe the signatures of a crossover between a thermal and a quantum behavior in the phase slip regimes. We find that phase slips are stable even at the lowest temperatures and that no hotspot is formed. The photoresponse of these nanowires is measured as a function of the light irradiation wavelength and temperature and exhibits a behavior comparable with previous results obtained on thicker films.

  18. Room Temperature Source of Single Photons of Definite Polarization

    SciTech Connect

    Lukishova, S.G.; Schmid, A.W.; Knox, R.; Freivald, P.; Bissel, L.J.; Boyd, R.W.; Stroud, Jr., C.R.; Marshall, K.L.

    2007-02-12

    A definite polarization in fluorescence from single emitters (dye molecules) at room temperature is demonstrated. A planar-aligned, nematic liquid-crystal host provides definite alignment of single dye molecules in a preferred direction. Well-defined polarized fluorescence from single-emitters (single photon source) is important for applications in photonic quantum information. Polarized single-photon sources based on single-emitters, for example, are key hardware elements both for absolutely secure quantum communication and quantum computation systems.

  19. Protecting single-photon entangled state from photon loss with noiseless linear amplification

    NASA Astrophysics Data System (ADS)

    Zhang, ShengLi; Yang, Song; Zou, XuBo; Shi, BaoSen; Guo, GuangCan

    2012-09-01

    Single-photon entanglement provides a valuable resource for quantum communication and quantum repeaters. However, single-photon entanglement is sensitive to photon loss. In this Brief Report, we show that a noiseless linear amplifier is an efficient tool for protecting single-photon entanglement. The performance of ideal noiseless linear amplification as well as the nonideal amplification with on-off detectors and heralded single photons are also investigated.

  20. III-Nitride high temperature single-photon sources

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Pallab; Deshpande, Saniya; Frost, Thomas; Hazari, Arnab

    2015-03-01

    Nitride based GaN and InGaN quantum dots are excellent single-photon emitters at high temperature owing to their wide bandgap and large exciton binding energy [1-5]. In this work, two different molecular beam epitaxy (MBE) grown nanostructures have been investigated for single-photon emission: InGaN/GaN disk-in-nanowire and InGaN/GaN self-organized quantum dot. Single-photon emission under both optical and electrical excitation has been observed from a single InGaN quantum contained in a GaN nanowire p-n junction. We demonstrate electrically driven single-photon emission, with a g (2)(0) = 0.35, from a single InGaN quantum dot emitting in the green spectral range (λ=520 nm) up to 125 K. Additionally, a self-organized InGaN/GaN single quantum dot diode was grown and fabricated. Emission from a single quantum dot (λ=620 nm) shows single-photon emission with g(2)(0) = 0.29 at room temperature. On-demand single-photon emission by electrical pumping of the quantum dot at an excitation repetition rate of 200 MHz was demonstrated.

  1. Characterization of the nonclassical nature of conditionally prepared single photons

    SciTech Connect

    U'Ren, Alfred B.; Silberhorn, Christine; Ball, Jonathan L.; Banaszek, Konrad; Walmsley, Ian A.

    2005-08-15

    A reliable single photon source is a prerequisite for linear optical quantum computation and for secure quantum key distribution. A criterion yielding a conclusive test of the single photon character of a given source, attainable with realistic detectors, is therefore highly desirable. In the context of heralded single photon sources, such a criterion should be sensitive to the effects of higher photon number contributions, and to vacuum introduced through optical losses, which tend to degrade source performance. In this Rapid Communication we present, theoretically and experimentally, a criterion meeting the above requirements.

  2. Single photon emission from ZnO nanoparticles

    SciTech Connect

    Choi, Sumin; Ton-That, Cuong; Phillips, Matthew R.; Aharonovich, Igor; Johnson, Brett C.; Castelletto, Stefania

    2014-06-30

    Room temperature single photon emitters are very important resources for photonics and emerging quantum technologies. In this work, we study single photon emission from defect centers in 20 nm zinc oxide (ZnO) nanoparticles. The emitters exhibit bright broadband fluorescence in the red spectral range centered at 640 nm with polarized excitation and emission. The studied emitters showed continuous blinking; however, bleaching can be suppressed using a polymethyl methacrylate coating. Furthermore, hydrogen termination increased the density of single photon emitters. Our results will contribute to the identification of quantum systems in ZnO.

  3. Single-photon and photon pair emission from MOVPE-grown In(Ga)As quantum dots: shifting the emission wavelength from 1.0 to 1.3 μm

    NASA Astrophysics Data System (ADS)

    Kettler, Jan; Paul, Matthias; Olbrich, Fabian; Zeuner, Katharina; Jetter, Michael; Michler, Peter

    2016-03-01

    InAs quantum dots grown on a GaAs substrate have been one of the most successful semiconductor material systems to demonstrate single-photon-based quantum optical phenomena. In this context, we present the feasibility to extend the low-temperature photoluminescence emission range of In(Ga)As/GaAs quantum dots grown by metal-organic vapor-phase epitaxy from the typical window between 880 and 960 nm to wavelengths above 1.3 μm. A low quantum dot density can be obtained throughout this range, enabling the demonstration of single- and cascaded photon emission. We further analyze polarization-resolved micro-photoluminescence from a large number of individual quantum dots with respect to anisotropy and size of the underlying fine-structure splittings in the emission spectra. For samples with elevated emission wavelengths, we observe an increasing tendency of the emitted photons to be polarized along the main crystal axes.

  4. Seeing single photons

    NASA Astrophysics Data System (ADS)

    Holmes, Rebecca

    2016-12-01

    The decades-old question of whether humans can see individual photons is on the brink of being answered thanks to advances in quantum optics. A positive result would let us use human observers as “detectors” to explore quantum effects such as entanglement, as Rebecca Holmes explains

  5. Purification of a single-photon nonlinearity

    PubMed Central

    Snijders, H.; Frey, J. A.; Norman, J.; Bakker, M. P.; Langman, E. C.; Gossard, A.; Bowers, J. E.; van Exter, M. P.; Bouwmeester, D.; Löffler, W.

    2016-01-01

    Single photon nonlinearities based on a semiconductor quantum dot in an optical microcavity are a promising candidate for integrated optical quantum information processing nodes. In practice, however, the finite quantum dot lifetime and cavity-quantum dot coupling lead to reduced fidelity. Here we show that, with a nearly polarization degenerate microcavity in the weak coupling regime, polarization pre- and postselection can be used to restore high fidelity. The two orthogonally polarized transmission amplitudes interfere at the output polarizer; for special polarization angles, which depend only on the device cooperativity, this enables cancellation of light that did not interact with the quantum dot. With this, we can transform incident coherent light into a stream of strongly correlated photons with a second-order correlation value up to 40, larger than previous experimental results, even in the strong-coupling regime. This purification technique might also be useful to improve the fidelity of quantum dot based logic gates. PMID:27573361

  6. Purification of a single-photon nonlinearity

    NASA Astrophysics Data System (ADS)

    Snijders, H.; Frey, J. A.; Norman, J.; Bakker, M. P.; Langman, E. C.; Gossard, A.; Bowers, J. E.; van Exter, M. P.; Bouwmeester, D.; Löffler, W.

    2016-08-01

    Single photon nonlinearities based on a semiconductor quantum dot in an optical microcavity are a promising candidate for integrated optical quantum information processing nodes. In practice, however, the finite quantum dot lifetime and cavity-quantum dot coupling lead to reduced fidelity. Here we show that, with a nearly polarization degenerate microcavity in the weak coupling regime, polarization pre- and postselection can be used to restore high fidelity. The two orthogonally polarized transmission amplitudes interfere at the output polarizer; for special polarization angles, which depend only on the device cooperativity, this enables cancellation of light that did not interact with the quantum dot. With this, we can transform incident coherent light into a stream of strongly correlated photons with a second-order correlation value up to 40, larger than previous experimental results, even in the strong-coupling regime. This purification technique might also be useful to improve the fidelity of quantum dot based logic gates.

  7. Highly Directional Room-Temperature Single Photon Device.

    PubMed

    Livneh, Nitzan; Harats, Moshe G; Istrati, Daniel; Eisenberg, Hagai S; Rapaport, Ronen

    2016-04-13

    One of the most important challenges in modern quantum optical applications is the demonstration of efficient, scalable, on-chip single photon sources, which can operate at room temperature. In this paper we demonstrate a room-temperature single photon source based on a single colloidal nanocrystal quantum dot positioned inside a circular bulls-eye shaped hybrid metal-dielectric nanoantenna. Experimental results show that 20% of the photons are emitted into a very low numerical aperture (NA < 0.25), a 20-fold improvement over a free-standing quantum dot, and with a probability of more than 70% for a single photon emission. With an NA = 0.65 more than 35% of the single photon emission is collected. The single photon purity is limited only by emission from the metal, an obstacle that can be bypassed with careful design and fabrication. The concept presented here can be extended to many other types of quantum emitters. Such a device paves a promising route for a high purity, high efficiency, on-chip single photon source operating at room temperature.

  8. Single-photon quadratic optomechanics

    PubMed Central

    Liao, Jie-Qiao; Nori, Franco

    2014-01-01

    We present exact analytical solutions to study the coherent interaction between a single photon and the mechanical motion of a membrane in quadratic optomechanics. We consider single-photon emission and scattering when the photon is initially inside the cavity and in the fields outside the cavity, respectively. Using our solutions, we calculate the single-photon emission and scattering spectra, and find relations between the spectral features and the system's inherent parameters, such as: the optomechanical coupling strength, the mechanical frequency, and the cavity-field decay rate. In particular, we clarify the conditions for the phonon sidebands to be visible. We also study the photon-phonon entanglement for the long-time emission and scattering states. The linear entropy is employed to characterize this entanglement by treating it as a bipartite one between a single mode of phonons and a single photon. PMID:25200128

  9. Crosstalk-free operation of multielement superconducting nanowire single-photon detector array integrated with single-flux-quantum circuit in a 0.1 W Gifford-McMahon cryocooler.

    PubMed

    Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Makise, Kazumasa; Wang, Zhen

    2012-07-15

    We demonstrate the successful operation of a multielement superconducting nanowire single-photon detector (SSPD) array integrated with a single-flux-quantum (SFQ) readout circuit in a compact 0.1 W Gifford-McMahon cryocooler. A time-resolved readout technique, where output signals from each element enter the SFQ readout circuit with finite time intervals, revealed crosstalk-free operation of the four-element SSPD array connected with the SFQ readout circuit. The timing jitter and the system detection efficiency were measured to be 50 ps and 11.4%, respectively, which were comparable to the performance of practical single-pixel SSPD systems.

  10. Ultrafast electrical control of a resonantly driven single photon source

    SciTech Connect

    Cao, Y.; Bennett, A. J. Ellis, D. J. P.; Shields, A. J.; Farrer, I.; Ritchie, D. A.

    2014-08-04

    We demonstrate generation of a pulsed stream of electrically triggered single photons in resonance fluorescence, by applying high frequency electrical pulses to a single quantum dot in a p-i-n diode under resonant laser excitation. Single photon emission was verified, with the probability of multiple photon emission reduced to 2.8%. We show that despite the presence of charge noise in the emission spectrum of the dot, resonant excitation acts as a “filter” to generate narrow bandwidth photons.

  11. Incoherent control of Goos-Hänchen shifts in a four-level InGaN/GaN quantum dot nanostructure

    NASA Astrophysics Data System (ADS)

    Solookinejad, G.; Panahi, M.; Ahmadi Sangachin, E.; Asadpour, Seyyed Hossein

    2016-04-01

    In this paper, we propose a new configuration for manipulating Goos-Hänchen (GH) shifts in reflected and transmitted probe beams in a fixed geometrical scheme with a confined four-level InGaN/GaN quantum dot nanostructure. Here, the four-level quantum dot nanostructure is driven by a weak probe light, a coherent coupling field, and two broadband polarized fields that serve as the incoherent pumping fields. We theoretically show that by modulation of the external coupling field, incoherent pumping rates, and detuning of the probe light, the GH shifts in the reflected and transmitted probe light can be controlled. Our results show that enhanced GH shifts of reflected and transmitted probe beams can be obtained by simultaneous use of incoherent pumping rates and detuning of the probe light. Moreover, we find that the GH shifts in both reflected and transmitted probe beams can be negative or positive at certain angles of the incident probe field. Thus, these results may provide some new possibilities for technological applications in all-optical systems based on nanostructure devices.

  12. Metal-organic vapor-phase epitaxy-grown ultra-low density InGaAs/GaAs quantum dots exhibiting cascaded single-photon emission at 1.3 μm

    SciTech Connect

    Paul, Matthias Kettler, Jan; Zeuner, Katharina; Clausen, Caterina; Jetter, Michael; Michler, Peter

    2015-03-23

    By metal-organic vapor-phase epitaxy, we have fabricated InGaAs quantum dots on GaAs substrate with an ultra-low lateral density (<10{sup 7} cm{sup −2}). The photoluminescence emission from the quantum dots is shifted to the telecom O-band at 1.31 μm by an InGaAs strain reducing layer. In time-resolved measurements, we find fast decay times for exciton (∼600 ps) and biexciton (∼300 ps). We demonstrate triggered single-photon emission (g{sup (2)}(0)=0.08) as well as cascaded emission from the biexciton decay. Our results suggest that these quantum dots can compete with their counterparts grown by state-of-the-art molecular beam epitaxy.

  13. Study of narrowband single photon emitters in polycrystalline diamond films

    SciTech Connect

    Sandstrom, Russell G.; Shimoni, Olga; Martin, Aiden A.; Aharonovich, Igor

    2014-11-03

    Quantum information processing and integrated nanophotonics require robust generation of single photon emitters on demand. In this work, we demonstrate that diamond films grown on a silicon substrate by microwave plasma chemical vapor deposition can host bright, narrowband single photon emitters in the visible—near infra-red spectral range. The emitters possess fast lifetime (∼several ns), absolute photostability, and exhibit full polarization at excitation and emission. Pulsed and continuous laser excitations confirm their quantum behaviour at room temperature, while low temperature spectroscopy is performed to investigate inhomogeneous broadening. Our results advance the knowledge of solid state single photon sources and open pathways for their practical implementation in quantum communication and quantum information processing.

  14. Experimental investigation towards a periodically pumped single-photon source

    NASA Astrophysics Data System (ADS)

    Bödefeld, C.; Ebbecke, J.; Toivonen, J.; Sopanen, M.; Lipsanen, H.; Wixforth, A.

    2006-07-01

    Experiments towards a periodically pumped single-photon source are presented. The lateral piezoelectric field of a surface acoustic wave dissociates laser-generated two-dimensional excitons into electrons and holes. These carriers are separated by the wave potential and are transported over macroscopic length scales without recombining. When reaching a stress-induced quantum dot in the quantum well they periodically populate the zero-dimensional states and recombine, emitting single photons periodically in time according to the surface acoustic-wave frequency. We have successfully reduced the number of pumped quantum dots down to 100 and have detected a strong blinking photoluminescence signal. By further reducing the number of quantum dots down to 1 a periodically pumped single photon source could be realized.

  15. A diamond nanowire single-photon source.

    PubMed

    Babinec, Thomas M; Hausmann, Birgit J M; Khan, Mughees; Zhang, Yinan; Maze, Jeronimo R; Hemmer, Philip R; Loncar, Marko

    2010-03-01

    The development of a robust light source that emits one photon at a time will allow new technologies such as secure communication through quantum cryptography. Devices based on fluorescent dye molecules, quantum dots and carbon nanotubes have been demonstrated, but none has combined a high single-photon flux with stable, room-temperature operation. Luminescent centres in diamond have recently emerged as a stable alternative, and, in the case of nitrogen-vacancy centres, offer spin quantum bits with optical readout. However, these luminescent centres in bulk diamond crystals have the disadvantage of low photon out-coupling. Here, we demonstrate a single-photon source composed of a nitrogen-vacancy centre in a diamond nanowire, which produces ten times greater flux than bulk diamond devices, while using ten times less power. This result enables a new class of devices for photonic and quantum information processing based on nanostructured diamond, and could have a broader impact in nanoelectromechanical systems, sensing and scanning probe microscopy.

  16. CMOS-compatible photonic devices for single-photon generation

    NASA Astrophysics Data System (ADS)

    Xiong, Chunle; Bell, Bryn; Eggleton, Benjamin J.

    2016-09-01

    Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal-oxide-semiconductor (CMOS)-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon) and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

  17. Characterization of photon statistics in a single-photon source via variable attenuation

    SciTech Connect

    Zhang Shengli; Zou Xubo; Li Chuanfeng; Guo Guangcan; Jin Chenhui

    2009-10-15

    We propose a simple but effective scheme for characterizing photon-number statistics of a practical single-photon source. In this scheme, the variable attenuation method which frequently appears in decoy state quantum cryptography is utilized here to enhance the estimation of photon-number statistics. A much stricter bound for vacuum and single-photon proportions is obtained and this result, in turn, is shown to be applicable to the unconditional secure quantum cryptographic communication with single-photon devices.

  18. Experimental generation of single photons via active multiplexing

    SciTech Connect

    Ma Xiaosong; Zotter, Stefan; Kofler, Johannes; Jennewein, Thomas; Zeilinger, Anton

    2011-04-15

    An on-demand single-photon source is a fundamental building block in quantum science and technology. We experimentally demonstrate the proof of concept for a scheme to generate on-demand single photons via actively multiplexing several heralded photons probabilistically produced from pulsed spontaneous parametric down-conversions (SPDCs). By utilizing a four-photon-pair source, an active feed-forward technique, and an ultrafast single-photon router, we show a fourfold enhancement of the output photon rate. Simultaneously, we maintain the quality of the output single-photon states, confirmed by correlation measurements. We also experimentally verify, via Hong-Ou-Mandel interference, that the router does not affect the indistinguishability of the single photons. Furthermore, we give numerical simulations, which indicate that photons based on multiplexing of four SPDC sources can outperform the heralding based on highly advanced photon-number-resolving detectors. Our results show a route for on-demand single-photon generation and the practical realization of scalable linear optical quantum-information processing.

  19. Direct detection of a single photon by humans

    PubMed Central

    Tinsley, Jonathan N.; Molodtsov, Maxim I.; Prevedel, Robert; Wartmann, David; Espigulé-Pons, Jofre; Lauwers, Mattias; Vaziri, Alipasha

    2016-01-01

    Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds. PMID:27434854

  20. Single-photon emission at 1.55 μm from MOVPE-grown InAs quantum dots on InGaAs/GaAs metamorphic buffers

    NASA Astrophysics Data System (ADS)

    Paul, Matthias; Olbrich, Fabian; Höschele, Jonatan; Schreier, Susanne; Kettler, Jan; Portalupi, Simone Luca; Jetter, Michael; Michler, Peter

    2017-07-01

    By metal-organic vapor-phase epitaxy, we have fabricated InAs quantum dots (QDs) on InGaAs/GaAs metamorphic buffer layers on a GaAs substrate with area densities that allow addressing single quantum dots. The photoluminescence emission from the quantum dots is shifted to the telecom C-band at 1.55 μm with a high yield due to the reduced stress in the quantum dots. The lowered residual strain at the surface of the metamorphic buffer layer results in a reduced lattice mismatch between the quantum dot material and growth surface. The quantum dots exhibit resolution-limited linewidths (mean value: 59 μeV) and low fine-structure splittings. Furthermore, we demonstrate single-photon emission ( g ( 2 ) ( 0 ) = 0.003 ) at 1.55 μm and decay times on the order of 1.4 ns comparable to InAs QDs directly deposited on GaAs substrates. Our results suggest that these quantum dots can not only compete with their counterparts deposited on InP substrates but also constitute an InAs/GaAs-only approach for the development of non-classical light sources in the telecom C-band.

  1. Discriminating orthogonal single-photon images

    NASA Astrophysics Data System (ADS)

    Broadbent, Curtis J.; Zerom, Petros; Shin, Heedeuk; Howell, John C.; Boyd, Robert W.

    2009-03-01

    We can encode an image from an orthogonal basis set onto a single photon from a downconverted pair via the use of an amplitude mask. We can then discriminate the image imprinted on the photon from other images in the set using holographic-matched filtering techniques. We demonstrate this procedure experimentally for an image space of two objects, and we discuss the possibility of applying this method to a much larger image space. This process could have important implications for the manipulation of images at the quantum level.

  2. Enhancement of Single-Photon Sources with Metamaterials

    NASA Astrophysics Data System (ADS)

    Shalaginov, M. Y.; Bogdanov, S.; Vorobyov, V. V.; Lagutchev, A. S.; Kildishev, A. V.; Akimov, A. V.; Boltasseva, A.; Shalaev, V. M.

    2015-06-01

    Scientists are looking for new, breakthrough solutions that can greatly advance computing and networking systems. These solutions will involve quantum properties of matter and light as promised by the ongoing experimental and theoretical work in the areas of quantum computation and communication. Quantum photonics is destined to play a central role in the development of such technologies due to the high transmission capacity and outstanding low-noise properties of photonic information channels. Among the vital problems to be solved in this direction, are efficient generation and collection of single photons. One approach to tackle these problems is based on engineering emission properties of available single-photon sources using metamaterials. Metamaterials are artificially engineered structures with sub-wavelength features whose optical properties go beyond the limitations of conventional materials. As promising single-photon sources, we have chosen nitrogen-vacancy (NV) color centers in diamond, which are capable to operate stably in a single-photon regime at room temperature in a solid state environment. In this chapter, we report both theoretical and experimental studies of the radiation from a nanodiamond single NV center placed near a hyperbolic metamaterial (HMM). In particular, we derive the reduction of excited-state lifetime and the enhancement of collected single-photon emission rate and compare them with the experimental observations. These results could be of great impact for future integrated quantum sources, especially owing to a CMOS-compatible approach to HMM synthesis.

  3. A solid-state single-photon filter

    NASA Astrophysics Data System (ADS)

    de Santis, Lorenzo; Antón, Carlos; Reznychenko, Bogdan; Somaschi, Niccolo; Coppola, Guillaume; Senellart, Jean; Gómez, Carmen; Lemaître, Aristide; Sagnes, Isabelle; White, Andrew G.; Lanco, Loïc; Auffèves, Alexia; Senellart, Pascale

    2017-07-01

    A strong limitation of linear optical quantum computing is the probabilistic operation of two-quantum-bit gates based on the coalescence of indistinguishable photons. A route to deterministic operation is to exploit the single-photon nonlinearity of an atomic transition. Through engineering of the atom-photon interaction, phase shifters, photon filters and photon-photon gates have been demonstrated with natural atoms. Proofs of concept have been reported with semiconductor quantum dots, yet limited by inefficient atom-photon interfaces and dephasing. Here, we report a highly efficient single-photon filter based on a large optical nonlinearity at the single-photon level, in a near-optimal quantum-dot cavity interface. When probed with coherent light wavepackets, the device shows a record nonlinearity threshold around 0.3 ± 0.1 incident photons. We demonstrate that 80% of the directly reflected light intensity consists of a single-photon Fock state and that the two- and three-photon components are strongly suppressed compared with the single-photon one.

  4. Multi-photon absorption limits to heralded single photon sources

    PubMed Central

    Husko, Chad A.; Clark, Alex S.; Collins, Matthew J.; De Rossi, Alfredo; Combrié, Sylvain; Lehoucq, Gaëlle; Rey, Isabella H.; Krauss, Thomas F.; Xiong, Chunle; Eggleton, Benjamin J.

    2013-01-01

    Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g(2)(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources. PMID:24186400

  5. Towards a quasi-deterministic single-photon source

    NASA Astrophysics Data System (ADS)

    Peters, N. A.; Arnold, K. J.; VanDevender, A. P.; Jeffrey, E. R.; Rangarajan, R.; Hosten, O.; Barreiro, J. T.; Altepeter, J. B.; Kwiat, P. G.

    2006-08-01

    A source of single photons allows secure quantum key distribution, in addition, to being a critical resource for linear optics quantum computing. We describe our progress on deterministically creating single photons from spontaneous parametric downconversion, an extension of the Pittman, Jacobs and Franson scheme [Phys. Rev A, v66, 042303 (2002)]. Their idea was to conditionally prepare single photons by measuring one member of a spontaneously emitted photon pair and storing the remaining conditionally prepared photon until a predetermined time, when it would be "deterministically" released from storage. Our approach attempts to improve upon this by recycling the pump pulse in order to decrease the possibility of multiple-pair generation, while maintaining a high probability of producing a single pair. Many of the challenges we discuss are central to other quantum information technologies, including the need for low-loss optical storage, switching and detection, and fast feed-forward control.

  6. Multi-photon absorption limits to heralded single photon sources

    NASA Astrophysics Data System (ADS)

    Husko, Chad A.; Clark, Alex S.; Collins, Matthew J.; de Rossi, Alfredo; Combrié, Sylvain; Lehoucq, Gaëlle; Rey, Isabella H.; Krauss, Thomas F.; Xiong, Chunle; Eggleton, Benjamin J.

    2013-11-01

    Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g(2)(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources.

  7. A silicon carbide room-temperature single-photon source

    NASA Astrophysics Data System (ADS)

    Castelletto, S.; Johnson, B. C.; Ivády, V.; Stavrias, N.; Umeda, T.; Gali, A.; Ohshima, T.

    2014-02-01

    Over the past few years, single-photon generation has been realized in numerous systems: single molecules, quantum dots, diamond colour centres and others. The generation and detection of single photons play a central role in the experimental foundation of quantum mechanics and measurement theory. An efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing. Here we report the identification and formation of ultrabright, room-temperature, photostable single-photon sources in a device-friendly material, silicon carbide (SiC). The source is composed of an intrinsic defect, known as the carbon antisite-vacancy pair, created by carefully optimized electron irradiation and annealing of ultrapure SiC. An extreme brightness (2×106 counts s-1) resulting from polarization rules and a high quantum efficiency is obtained in the bulk without resorting to the use of a cavity or plasmonic structure. This may benefit future integrated quantum photonic devices.

  8. Single photon searches at PEP

    SciTech Connect

    Hollebeek, R.

    1985-12-01

    The MAC and ASP searches for events with a single photon and no other observed particles are reviewed. New results on the number of neutrino generations and limits on selection, photino, squark and gluino masses from the ASP experiment are presented.

  9. Graphene-Based Josephson-Junction Single-Photon Detector

    NASA Astrophysics Data System (ADS)

    Walsh, Evan D.; Efetov, Dmitri K.; Lee, Gil-Ho; Heuck, Mikkel; Crossno, Jesse; Ohki, Thomas A.; Kim, Philip; Englund, Dirk; Fong, Kin Chung

    2017-08-01

    We propose to use graphene-based Josephson junctions (GJJs) to detect single photons in a wide electromagnetic spectrum from visible to radio frequencies. Our approach takes advantage of the exceptionally low electronic heat capacity of monolayer graphene and its constricted thermal conductance to its phonon degrees of freedom. Such a system could provide high-sensitivity photon detection required for research areas including quantum information processing and radio astronomy. As an example, we present our device concepts for GJJ single-photon detectors in both the microwave and infrared regimes. The dark count rate and intrinsic quantum efficiency are computed based on parameters from a measured GJJ, demonstrating feasibility within existing technologies.

  10. Plasmonic nanoantenna based triggered single-photon source

    NASA Astrophysics Data System (ADS)

    Straubel, J.; Filter, R.; Rockstuhl, C.; Słowik, K.

    2016-05-01

    Highly integrated single-photon sources are key components in future quantum-optical circuits. Whereas the probabilistic generation of single photons can routinely be done by now, their triggered generation is a much greater challenge. Here, we describe the triggered generation of single photons in a hybrid plasmonic device. It consists of a lambda-type quantum emitter coupled to a multimode optical nanoantenna. For moderate interaction strengths between the subsystems, the description of the quantum optical evolution can be simplified by an adiabatic elimination of the electromagnetic fields of the nanoantenna modes. This leads to an insightful analysis of the emitter's dynamics, entails the opportunity to understand the physics of the device, and to identify parameter regimes for a desired operation. Even though the approach presented in this work is general, we consider a simple exemplary design of a plasmonic nanoantenna, made of two silver nanorods, suitable for triggered generation of single photons. The investigated device realizes single photons, triggered, potentially at high rates, and using low device volumes.

  11. Direct fiber-coupled single photon source based on a photonic crystal waveguide

    SciTech Connect

    Ahn, Byeong-Hyeon Lee, Chang-Min; Lim, Hee-Jin; Schlereth, Thomas W.; Kamp, Martin; Höfling, Sven; Lee, Yong-Hee

    2015-08-24

    A single photon source plays a key role in quantum applications such as quantum computers and quantum communications. Epitaxially grown quantum dots are one of the promising platforms to implement a good single photon source. However, it is challenging to realize an efficient single photon source based on semiconductor materials due to their high refractive index. Here we demonstrate a direct fiber coupled single photon source with high collection efficiency by employing a photonic crystal (PhC) waveguide and a tapered micro-fiber. To confirm the single photon nature, the second-order correlation function g{sup (2)}(τ) is measured with a Hanbury Brown-Twiss setup. The measured g{sup (2)}(0) value is 0.15, and we can estimate 24% direct collection efficiency from a quantum dot to the fiber.

  12. Tunable single-photon frequency conversion in a Sagnac interferometer

    NASA Astrophysics Data System (ADS)

    Yan, Wei-Bin; Huang, Jin-Feng; Fan, Heng

    2013-12-01

    Quantum information carriers like photons might be manipulated, stored and transmitted in different quantum systems. It is important to integrate those systems efficiently. The capability of converting photons from one wavelength to another wavelength is a key requirement for combining the photons in telecommunications band for quantum transmission and the photons in near-visible band for quantum storage. Here, we investigate the tunable single-photon frequency conversion in the five-level emitter-Sagnac interferometer system. We show that the efficient single-photon conversion can be achieved in this scheme, at the same time, the frequencies of the input and output photons can be tuned in a large scale by controlling the frequencies and Rabi frequencies of the external driving fields. The realization of this scheme may lead to the efficient combination of quantum storage system with the quantum communication system.

  13. Single-photon emitters in GaSe

    NASA Astrophysics Data System (ADS)

    Tonndorf, Philipp; Schwarz, Stefan; Kern, Johannes; Niehues, Iris; Del Pozo-Zamudio, Osvaldo; Dmitriev, Alexander I.; Bakhtinov, Anatoly P.; Borisenko, Dmitry N.; Kolesnikov, Nikolai N.; Tartakovskii, Alexander I.; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf

    2017-06-01

    Single-photon sources are important building blocks for quantum information technology. Emitters based on solid-state systems provide a viable route to integration in photonic devices. Here, we report on single-photon emitters in the layered semiconductor GaSe. We identify the exciton and biexciton transition of the quantum emitters with power-dependent photoluminescence and photon statistics measurements. We find evidence that the localization of the excitons is related to deformations of the GaSe crystal, caused by nanoscale selenium inclusions, which are incorporated in the crystal. These deformations give rise to local strain fields, which induce confinement potentials for the excitons. This mechanism lights the way for the controlled positioning of single-photon emitters in GaSe on the nanoscale.

  14. Efficient Generation of Frequency-Multiplexed Entangled Single Photons

    NASA Astrophysics Data System (ADS)

    Qiu, Tian-Hui; Xie, Min

    2016-12-01

    We present two schemes to generate frequency-multiplexed entangled (FME) single photons by coherently mapping photonic entanglement into and out of a quantum memory based on Raman interactions. By splitting a single photon and performing subsequent state transfer, we separate the generation of entanglement and its frequency conversion, and find that the both progresses have the characteristic of inherent determinacy. Our theory can reproduce the prominent features of observed results including pulse shapes and the condition for deterministically generating the FME single photons. The schemes are suitable for the entangled photon pairs with a wider frequency range, and could be immune to the photon loss originating from cavity-mode damping, spontaneous emission, and the dephasing due to atomic thermal motion. The sources might have significant applications in wavelength-division-multiplexing quantum key distribution.

  15. Strategies for optical integration of single-photon sources

    NASA Astrophysics Data System (ADS)

    Benson, Oliver; Schell, Andreas W.; Neumer, Tanja; Shi, Qiang; Kaschke, Johannes; Fischer, Joachim; Wegener, Martin

    2015-02-01

    Single-photon sources based on solid-state emitters, like quantum dots, molecules or defect centers in diamond, are one of the key components for an integrated quantum technology. Here, we will show different strategies used in order to integrate single-photon emitters. Among others, we introduce an hybrid approach using photon emission from defect centers in diamond and laser-written photonic structures. Waveguides, microresonators, and optical antennas can be fabricated and oriented with respect to the single emitters. We describe our general approach before we specifically address the problem of efficient single-photon collection through optical antennas. We discuss the limitations of the method, its potential for scalability as well as its extension towards optical sensing applications.

  16. Theoretical and experimental investigation on superconducting nanowire single-photon detectors

    NASA Astrophysics Data System (ADS)

    Dai, Yue

    2017-02-01

    Single-photon detectors have been widely used in many vital fields, such as quantum teleportation and quantum computation. Compared with other single-photon detectors, superconducting nanowire single-photon detector exhibits relatively wide response spectrum, low dark count rate and high detection efficiency. The principle of superconducting nanowire single-photon detector is demonstrated, especially on the process of the generation and the diffusion of the hotspot, and the simulation is done to illustrate this process. Many important parameters of superconducting nanowire single-photon detector are measured, such as R-T curve and photon response. Through the analysis of experimental data, the approach to improve the performance of superconducting nanowire single-photon detector is proposed.

  17. Experimental quasi-single-photon transmission from satellite to earth.

    PubMed

    Yin, Juan; Cao, Yuan; Liu, Shu-Bin; Pan, Ge-Sheng; Wang, Jin-Hong; Yang, Tao; Zhang, Zhong-Ping; Yang, Fu-Min; Chen, Yu-Ao; Peng, Cheng-Zhi; Pan, Jian-Wei

    2013-08-26

    Free-space quantum communication with satellites opens a promising avenue for global secure quantum network and large-scale test of quantum foundations. Recently, numerous experimental efforts have been carried out towards this ambitious goal. However, one essential step--transmitting single photons from the satellite to the ground with high signal-to-noise ratio (SNR) at realistic environments--remains experimental challenging. Here, we report a direct experimental demonstration of the satellite-ground transmission of a quasi-single-photon source. In the experiment, single photons (~0.85 photon per pulse) are generated by reflecting weak laser pulses back to earth with a cube-corner retro-reflector on the satellite CHAMP, collected by a 600-mm diameter telescope at the ground station, and finally detected by single-photon counting modules after 400-km free-space link transmission. With the help of high accuracy time synchronization, narrow receiver field-of-view and high-repetition-rate pulses (76 MHz), a SNR of better than 16:1 is obtained, which is sufficient for a secure quantum key distribution. Our experimental results represent an important step towards satellite-ground quantum communication.

  18. Single-photon multi-ports router based on the coupled cavity optomechanical system.

    PubMed

    Li, Xun; Zhang, Wen-Zhao; Xiong, Biao; Zhou, Ling

    2016-12-22

    A scheme of single-photon multi-port router is put forward by coupling two optomechanical cavities with waveguides. It is shown that the coupled two optomechanical cavities can exhibit photon blockade effect, which is generated from interference of three mode interaction. A single-photon travel along the system is calculated. The results show that the single photon can be controlled in the multi-port system because of the radiation pressure, which should be useful for constructing quantum network.

  19. Steady-state linear optical properties and Kerr nonlinear optical response of a four-level quantum dot with phonon-assisted transition

    NASA Astrophysics Data System (ADS)

    Yan-Chao, She; Ting-Ting, Luo; Wei-Xi, Zhang; Mao-Wu, Ran; Deng-Long, Wang

    2016-01-01

    The linear optical properties and Kerr nonlinear optical response in a four-level loop configuration GaAs/AlGaAs semiconductor quantum dot are analytically studied with the phonon-assisted transition (PAT). It is shown that the changes among a single electromagnetically induced transparency (EIT) window, a double EIT window and the amplification of the probe field in the absorption curves can be controlled by varying the strength of PAT κ. Meanwhile, double switching from the anomalous dispersion regime to the normal dispersion regime can likely be achieved by increasing the Rabi energy of the external optical control field. Furthermore, we demonstrate that the group velocity of the probe field can be practically regulated by varying the PAT and the intensity of the optical control field. In the nonlinear case, it is shown that the large SPM and XPM can be achieved as linear absorption vanishes simultaneously, and the PAT can suppress both third-order self-Kerr and the cross-Kerr nonlinear effect of the QD. Our study is much more practical than its atomic counterpart due to its flexible design and the controllable interference strength, and may provide some new possibilities for technological applications. Project supported by the National Natural Science Foundation of China (Grant No. 61367003), the Scientific Research Fund of Hunan Provincial Education Department, China (Grant No. 12A140), and the Scientific Research Fund of Guizhou Provincial Education Department, China (Grant Nos. KY[2015]384 and KY[2015]446).

  20. Investigation of quantum phase transitions in the spdf interacting boson model based on dual algebraic structures for the four-level pairing model

    NASA Astrophysics Data System (ADS)

    Jafarizadeh, M. A.; Jalili Majarshin, A.; Fouladi, N.; Ghapanvari, M.

    2016-09-01

    The building blocks of the interacting boson model (IBM) are associated with both s and d bosons for positive parity states. An extension of sd-IBM along these models to spdf-IBM can provide the appropriate framework to describe negative parity states. In this paper, a solvable extended transitional Hamiltonian based on the affine \\widehat{{SU}(1,1)} Lie algebra is proposed to describe low lying positive and negative parity states between the spherical and deformed gamma-unstable shape. Quantum phase transitions (QPTs) are investigated based on dual algebraic structures for the four-level pairing model. Numerical extraction to low-lying energy levels and transition rates within the control parameters of this evaluated Hamiltonian are presented for various N values. By reproducing the experimental results, the method based on the signatures of the phase transition, such as the expectation value of the boson number operators in the lowest excited states, are used to provide a better description of Ru isotopes in this transitional region.

  1. A gallium nitride single-photon source operating at 200 K.

    PubMed

    Kako, Satoshi; Santori, Charles; Hoshino, Katsuyuki; Götzinger, Stephan; Yamamoto, Yoshihisa; Arakawa, Yasuhiko

    2006-11-01

    Fundamentally secure quantum cryptography has still not seen widespread application owing to the difficulty of generating single photons on demand. Semiconductor quantum-dot structures have recently shown great promise as practical single-photon sources, and devices with integrated optical cavities and electrical-carrier injection have already been demonstrated. However, a significant obstacle for the application of commonly used III-V quantum dots to quantum-information-processing schemes is the requirement of liquid-helium cryogenic temperatures. Epitaxially grown gallium nitride quantum dots embedded in aluminium nitride have the potential for operation at much higher temperatures. Here, we report triggered single-photon emission from gallium nitride quantum dots at temperatures up to 200 K, a temperature easily reachable with thermo-electric cooling. Gallium nitride quantum dots also open a new wavelength region in the blue and near-ultraviolet portions of the spectrum for single-photon sources.

  2. Present Status and Future Prospects of Quantum Information Processing: With Special Focus on Optically Controlled Semiconductor Spins and Single-Photon Technologies

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yoshihisa

    2011-10-01

    The scheme of directly controlling electron spins trapped in semiconductor quantum dots or donor impurities as qubits using optical pulses has various advantages, such as the achievements of local excitation and fast operation, low power consumption, easy implementation of an interface with optical fiber communication networks, and the capability of transferring information to nuclear spins, which are expected to serve as quantum memories with a long coherence time. In this report, I introduce the present status of the research and development of this scheme and discuss its potential application to quantum information processing.

  3. Tomography of a Mode-Tunable Coherent Single-Photon Subtractor

    NASA Astrophysics Data System (ADS)

    Ra, Young-Sik; Jacquard, Clément; Dufour, Adrien; Fabre, Claude; Treps, Nicolas

    2017-07-01

    Single-photon subtraction plays important roles in optical quantum information processing as it provides a non-Gaussian characteristic in continuous-variable quantum information. While the conventional way of implementing single-photon subtraction based on a low-reflectance beam splitter works properly for a single-mode quantum state, it is unsuitable for a multimode quantum state because a single photon is subtracted from all multiple modes without maintaining their mode coherence. Here, we experimentally implement and characterize a mode-tunable coherent single-photon subtractor based on sum-frequency generation. It can subtract a single photon exclusively from one desired time-frequency mode of light or from a coherent superposition of multiple time-frequency modes. To experimentally characterize the time-frequency modes of the single-photon subtractor, we employ quantum process tomography based on coherent states. The mode-tunable coherent single-photon subtractor will be an essential element for realizing non-Gaussian quantum networks necessary to get a quantum advantage in information processing.

  4. Entangling single photons from independently tuned semiconductor nanoemitters.

    PubMed

    Sanaka, Kaoru; Pawlis, Alexander; Ladd, Thaddeus D; Sleiter, Darin J; Lischka, Klaus; Yamamoto, Yoshihisa

    2012-09-12

    Quantum communication systems based on nanoscale semiconductor devices is challenged by inhomogeneities from device to device. We address this challenge using ZnMgSe/ZnSe quantum-well nanostructures with local laser-based heating to tune the emission of single impurity-bound exciton emitters in two separate devices. The matched emission in combination with photon bunching enables quantum interference from the devices and allows the postselection of polarization-entangled single photons. The ability to entangle single photons emitted from nanometer-sized sources separated by macroscopic distances provides an essential step for a solid-state realization of a large-scale quantum optical network. This paves the way toward measurement-based entanglement generation between remote electron spins localized at macroscopically separated fluorine impurities.

  5. Protecting single-photon entanglement with practical entanglement source

    NASA Astrophysics Data System (ADS)

    Zhou, Lan; Ou-Yang, Yang; Wang, Lei; Sheng, Yu-Bo

    2017-06-01

    Single-photon entanglement (SPE) is important for quantum communication and quantum information processing. However, SPE is sensitive to photon loss. In this paper, we discuss a linear optical amplification protocol for protecting SPE. Different from the previous protocols, we exploit the practical spontaneous parametric down-conversion (SPDC) source to realize the amplification, for the ideal entanglement source is unavailable in current quantum technology. Moreover, we prove that the amplification using the entanglement generated from SPDC source as auxiliary is better than the amplification assisted with single photons. The reason is that the vacuum state from SPDC source will not affect the amplification, so that it can be eliminated automatically. This protocol may be useful in future long-distance quantum communications.

  6. A review on single photon sources in silicon carbide.

    PubMed

    Lohrmann, A; Johnson, B C; McCallum, J C; Castelletto, S

    2017-03-01

    This paper summarizes key findings in single-photon generation from deep level defects in silicon carbide (SiC) and highlights the significance of these individually addressable centers for emerging quantum applications. Single photon emission from various defect centers in both bulk and nanostructured SiC are discussed as well as their formation and possible integration into optical and electrical devices. The related measurement protocols, the building blocks of quantum communication and computation network architectures in solid state systems, are also summarized. This includes experimental methodologies developed for spin control of different paramagnetic defects, including the measurement of spin coherence times. Well established doping, and micro- and nanofabrication procedures for SiC may allow the quantum properties of paramagnetic defects to be electrically and mechanically controlled efficiently. The integration of single defects into SiC devices is crucial for applications in quantum technologies and we will review progress in this direction.

  7. A review on single photon sources in silicon carbide

    NASA Astrophysics Data System (ADS)

    Lohrmann, A.; Johnson, B. C.; McCallum, J. C.; Castelletto, S.

    2017-03-01

    This paper summarizes key findings in single-photon generation from deep level defects in silicon carbide (SiC) and highlights the significance of these individually addressable centers for emerging quantum applications. Single photon emission from various defect centers in both bulk and nanostructured SiC are discussed as well as their formation and possible integration into optical and electrical devices. The related measurement protocols, the building blocks of quantum communication and computation network architectures in solid state systems, are also summarized. This includes experimental methodologies developed for spin control of different paramagnetic defects, including the measurement of spin coherence times. Well established doping, and micro- and nanofabrication procedures for SiC may allow the quantum properties of paramagnetic defects to be electrically and mechanically controlled efficiently. The integration of single defects into SiC devices is crucial for applications in quantum technologies and we will review progress in this direction.

  8. Fast time-domain measurements on telecom single photons

    NASA Astrophysics Data System (ADS)

    Allgaier, Markus; Vigh, Gesche; Ansari, Vahid; Eigner, Christof; Quiring, Viktor; Ricken, Raimund; Brecht, Benjamin; Silberhorn, Christine

    2017-09-01

    Direct measurements on the temporal envelope of quantum light are a challenging task and not many examples are known because most classical pulse characterisation methods do not work on the single-photon level. Knowledge of both spectrum and timing can, however, give insights on properties that cannot be determined by the spectral intensity alone. While temporal measurements on single photons on timescales of tens of picoseconds are possible with superconducting photon detectors, and picosecond measurements have been performed using streak cameras, there are no commercial single-photon sensitive devices with femtosecond resolution available. While time-domain sampling using sum-frequency generation has already been exploited for such a measurement, inefficient conversion has necessitated long integration times to build the temporal profile. We demonstrate a highly efficient waveguided sum-frequency generation process in Lithium Niobate to measure the temporal envelope of single photons with femtosecond resolution with short enough acquisition time to provide a live-view of the measurement. We demonstrate the measurement technique and combine it with spectral measurements using a dispersive-fibre time-of-flight spectrometer to determine upper and lower bounds for the spectral purity of heralded single photons. The approach complements the joint spectral intensity measurements as a measure on the purity can be given without knowledge of the spectral phase.

  9. Cockroach optomotor responses below single photon level.

    PubMed

    Honkanen, Anna; Takalo, Jouni; Heimonen, Kyösti; Vähäsöyrinki, Mikko; Weckström, Matti

    2014-12-01

    Reliable vision in dim light depends on the efficient capture of photons. Moreover, visually guided behaviour requires reliable signals from the photoreceptors to generate appropriate motor reactions. Here, we show that at behavioural low-light threshold, cockroach photoreceptors respond to moving gratings with single-photon absorption events known as 'quantum bumps' at or below the rate of 0.1 s(-1). By performing behavioural experiments and intracellular recordings from photoreceptors under identical stimulus conditions, we demonstrate that continuous modulation of the photoreceptor membrane potential is not necessary to elicit visually guided behaviour. The results indicate that in cockroach motion detection, massive temporal and spatial pooling takes place throughout the eye under dim conditions, involving currently unknown neural processing algorithms. The extremely high night-vision capability of the cockroach visual system provides a roadmap for bio-mimetic imaging design.

  10. Noiseless Conditional Teleportation of a Single Photon.

    PubMed

    Fuwa, Maria; Toba, Shunsuke; Takeda, Shuntaro; Marek, Petr; Mišta, Ladislav; Filip, Radim; van Loock, Peter; Yoshikawa, Jun-Ichi; Furusawa, Akira

    2014-11-28

    We experimentally demonstrate the noiseless teleportation of a single photon by conditioning on quadrature Bell measurement results near the origin in phase space and thereby circumventing the photon loss that otherwise occurs even in optimal gain-tuned continuous-variable quantum teleportation. In general, thanks to this loss suppression, the noiseless conditional teleportation can preserve the negativity of the Wigner function for an arbitrary pure input state and an arbitrary pure entangled resource state. In our experiment, the positive value of the Wigner function at the origin for the unconditional output state, W(0,0)=0.015±0.001, becomes clearly negative after conditioning, W(0,0)=-0.025±0.005, illustrating the advantage of noiseless conditional teleportation.

  11. Circuit electromechanics with single photon strong coupling

    SciTech Connect

    Xue, Zheng-Yuan Yang, Li-Na; Zhou, Jian

    2015-07-13

    In circuit electromechanics, the coupling strength is usually very small. Here, replacing the capacitor in circuit electromechanics by a superconducting flux qubit, we show that the coupling among the qubit and the two resonators can induce effective electromechanical coupling which can attain the strong coupling regime at the single photon level with feasible experimental parameters. We use dispersive couplings among two resonators and the qubit while the qubit is also driven by an external classical field. These couplings form a three-wave mixing configuration among the three elements where the qubit degree of freedom can be adiabatically eliminated, and thus results in the enhanced coupling between the two resonators. Therefore, our work constitutes the first step towards studying quantum nonlinear effect in circuit electromechanics.

  12. Localised excitation of a single photon source by a nanowaveguide.

    PubMed

    Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; De Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

    2016-01-29

    Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10(-4) only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system.

  13. Localised excitation of a single photon source by a nanowaveguide

    NASA Astrophysics Data System (ADS)

    Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; de Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

    2016-01-01

    Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10-4 only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system.

  14. Localised excitation of a single photon source by a nanowaveguide

    PubMed Central

    Geng, Wei; Manceau, Mathieu; Rahbany, Nancy; Sallet, Vincent; De Vittorio, Massimo; Carbone, Luigi; Glorieux, Quentin; Bramati, Alberto; Couteau, Christophe

    2016-01-01

    Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10−4 only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system. PMID:26822999

  15. Pure single photons from a trapped atom source

    NASA Astrophysics Data System (ADS)

    Higginbottom, D. B.; Slodička, L.; Araneda, G.; Lachman, L.; Filip, R.; Hennrich, M.; Blatt, R.

    2016-09-01

    Single atoms or atom-like emitters are the purest source of single photons, they are intrinsically incapable of multi-photon emission. To demonstrate this degree of photon number-state purity we have realized a single-photon source using a single ion trapped at the common focus of high numerical aperture lenses. Our trapped-ion source produces single-photon pulses with {g}2(0)=(1.9+/- 0.2)× {10}-3 without any background subtraction. After subtracting detector dark counts the residual {g}2(0) is less than 3 × 10-4 (95% confidence interval). The multi-photon component of the source light field is low enough that we measure violation of a quantum non-Gaussian state witness, by this characterization the source output is indistinguishable from ideal attenuated single photons. In combination with efforts to enhance collection efficiency from single emitters, our results suggest that single trapped ions are not only ideal stationary qubits for quantum information processing, but promising sources of light for scalable optical quantum networks.

  16. Fast path and polarization manipulation of telecom wavelength single photons in lithium niobate waveguide devices.

    PubMed

    Bonneau, Damien; Lobino, Mirko; Jiang, Pisu; Natarajan, Chandra M; Tanner, Michael G; Hadfield, Robert H; Dorenbos, Sanders N; Zwiller, Val; Thompson, Mark G; O'Brien, Jeremy L

    2012-02-03

    We demonstrate fast polarization and path control of photons at 1550 nm in lithium niobate waveguide devices using the electro-optic effect. We show heralded single photon state engineering, quantum interference, fast state preparation of two entangled photons, and feedback control of quantum interference. These results point the way to a single platform that will enable the integration of nonlinear single photon sources and fast reconfigurable circuits for future photonic quantum information science and technology.

  17. Experimental optimal maximum-confidence discrimination and optimal unambiguous discrimination of two mixed single-photon states

    SciTech Connect

    Steudle, Gesine A.; Knauer, Sebastian; Herzog, Ulrike; Benson, Oliver; Stock, Erik; Bimberg, Dieter; Haisler, Vladimir A.

    2011-05-15

    We present an experimental implementation of optimum measurements for quantum state discrimination. Optimum maximum-confidence discrimination and optimum unambiguous discrimination of two mixed single-photon polarization states were performed. For the latter the states of rank 2 in a four-dimensional Hilbert space are prepared using both path and polarization encoding. Linear optics and single photons from a true single-photon source based on a semiconductor quantum dot are utilized.

  18. Patterning metamaterials for fast and efficient single-photon sources

    NASA Astrophysics Data System (ADS)

    Makarova, O. A.; Shalaginov, M. Y.; Bogdanov, S.; Guler, U.; Boltasseva, A.; Kildishev, A. V.; Shalaev, V. M.

    2017-02-01

    Solid state quantum emitters are prime candidates to realize fast on-demand single-photon sources. The improvement in photon emission and collection efficiencies for quantum emitters, such as nitrogen-vacancy (NV) centers in diamond, can be achieved by using a near-field coupling to nanophotonic structures. Plasmonic metamaterial structures with hyperbolic dispersion have been previously demonstrated to significantly increase the fluorescence decay rates from NV centers. However, the electromagnetic waves propagating inside the metamaterial must be outcoupled before they succumb to ohmic losses. We propose a nano-grooved hyperbolic metamaterial that improves the collection efficiency from a nanodiamond-based NV center by a factor of 4.3 compared to the case of coupling to a flat metamaterial. Our design can be utilized to achieve highly efficient and fast single-photon sources based on a variety of quantum emitters.

  19. Single photon emission computed tomography

    SciTech Connect

    Piez, C.W. Jr.; Holman, B.L.

    1985-07-01

    Single photon emission computed tomography (SPECT) is becoming an increasingly important part of routine clinical nuclear medicine. By providing tomographic reconstructions in multiple planes through the patient, SPECT expands the clinical applications in nuclear medicine as well as providing better contrast, edge definition and separation of target from background activities. Imaging techniques have been developed for the evaluation of regional cerebral blood flow using radiolabeled amines. Thus, cerebral functional imaging can be used in the diagnosis of acute cerebral infarction, cerebral vascular disease, dementia and epilepsy. SPECT plays a complementary role in the evaluation of coronary artery disease, particularly when it is coupled with thallium-201 and exercise testing. SPECT extends our diagnostic capabilities in additional areas, such as liver and bone scintigraphy as well as tumor imaging with gallium-67.

  20. Controlling photon transport in the single-photon weak-coupling regime of cavity optomechanics

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-Zhao; Cheng, Jiong; Liu, Jing-Yi; Zhou, Ling

    2015-06-01

    We study the photon statistics properties of few-photon transport in an optomechanical system where an optomechanical cavity couples to two empty cavities. By analytically deriving the one- and two-photon currents in terms of a zero-time-delayed two-order correlation function, we show that a photon blockade can be achieved in both the single-photon strong-coupling regime and the single-photon weak-coupling regime due to the nonlinear interacting and multipath interference. Furthermore, our systems can be applied as a quantum optical diode, a single-photon source, and a quantum optical capacitor. It is shown that this the photon transport controlling devices based on photon antibunching does not require the stringent single-photon strong-coupling condition. Our results provide a promising platform for the coherent manipulation of optomechanics, which has potential applications for quantum information processing and quantum circuit realization.

  1. The effect of impurities on linear and nonlinear absorption coefficient and refractive index of the spherical quantum dot four-level M-model the phenomenon of electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Damiri, H.; Askari, H. R.

    2017-01-01

    In this paper, the effect of impurities on the phenomenon of electromagnetically induced transparency in a spherical quantum dot with parabolic potential is examined. It is assumed that spherical quantum dot has configuration four levels model M. First, consider the polarization Z for light; rotating wave approximation approach, rotating coordinate system, as well as the density matrix approach, we examine the phenomenon of electromagnetically induced transparency in spherical quantum dot. Finally, with regard to impurities of the disorder, we review electromagnetically induced transparency and Changes resulting from the presence of impurities.

  2. Dynamically unpolarized single-photon source in diamond with intrinsic randomness

    PubMed Central

    Abe, Naofumi; Mitsumori, Yasuyoshi; Sadgrove, Mark; Edamatsu, Keiichi

    2017-01-01

    Polarization is one of the fundamental properties of light, providing numerous applications in science and technology. While ‘dynamically unpolarized’ single-photon sources are demanded for various quantum applications, such sources have never been explored. Here we demonstrate dynamically unpolarized single-photon emission from a single [111]-oriented nitrogen- vacancy centre in diamond, in which the single-photon stream is unpolarized, exhibiting intrinsic randomness with vanishing polarization correlation between time adjacent photons. These properties not only allow true random number generation, but may also enable fundamental tests in quantum physics. PMID:28443612

  3. Solid-state single-photon detectors

    NASA Astrophysics Data System (ADS)

    Zappa, Franco; Lacaita, Andrea L.; Cova, Sergio D.; Lovati, Piergiorgio G.

    1996-04-01

    This paper reviews the state of the art of some new photon-counting detectors. We measured the performance of various commercial silicon, germanium, and InGaAs/InP single-photon avalanche diodes (SPADs) in the 0.8- to 1.55-micrometer wavelength range. Optimized silicon devices reach 70% quantum efficiency at 800 nm and can work up to 1.1 micrometer. However, germanium and InGaAs SPADs are sensitive up to 1.4 and 1.6 micrometers, respectively, with a few percent quantum efficiency. In all samples we measured noise equivalent powers less than 10-15 W/Hz1/2. Compared with vacuum tubes, SPADs have different advantages such as reliability, roughness, low voltage and simple electronic requirements. Furthermore, it is easy to arrange them in the form of arrays, which are required in astronomy and luminescence measurements. Moreover we investigated the performance of a SPAD germanium quad sensor. By using proper driving electronics we avoided optical cross-talk between pixels and we present here the preliminary results of our experiments.

  4. Site-controlled InGaN/GaN single-photon-emitting diode

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Teng, Chu-Hsiang; Ku, Pei-Cheng; Deng, Hui

    2016-04-01

    We report single-photon emission from electrically driven site-controlled InGaN/GaN quantum dots. The device is fabricated from a planar light-emitting diode structure containing a single InGaN quantum well, using a top-down approach. The location, dimension, and height of each single-photon-emitting diode are controlled lithographically, providing great flexibility for chip-scale integration.

  5. Site-controlled InGaN/GaN single-photon-emitting diode

    SciTech Connect

    Zhang, Lei; Deng, Hui; Teng, Chu-Hsiang; Ku, Pei-Cheng

    2016-04-11

    We report single-photon emission from electrically driven site-controlled InGaN/GaN quantum dots. The device is fabricated from a planar light-emitting diode structure containing a single InGaN quantum well, using a top-down approach. The location, dimension, and height of each single-photon-emitting diode are controlled lithographically, providing great flexibility for chip-scale integration.

  6. Superior Optical Properties of Perovskite Nanocrystals as Single Photon Emitters.

    PubMed

    Hu, Fengrui; Zhang, Huichao; Sun, Chun; Yin, Chunyang; Lv, Bihu; Zhang, Chunfeng; Yu, William W; Wang, Xiaoyong; Zhang, Yu; Xiao, Min

    2015-12-22

    The power conversion efficiency of photovoltaic devices based on semiconductor perovskites has reached ∼20% after just several years of research efforts. With concomitant discoveries of other promising applications in lasers, light-emitting diodes, and photodetectors, it is natural to anticipate what further excitement these exotic perovskites could bring about. Here we report on the observation of single photon emission from single CsPbBr3 perovskite nanocrystals (NCs) synthesized from a facile colloidal approach. Compared with traditional metal-chalcogenide NCs, these CsPbBr3 NCs exhibit nearly 2 orders of magnitude increase in their absorption cross sections at similar emission colors. Moreover, the radiative lifetime of CsPbBr3 NCs is greatly shortened at both room and cryogenic temperatures to favor an extremely fast output of single photons. The above superior optical properties have paved the way toward quantum-light applications of perovskite NCs in various quantum information processing schemes.

  7. Total teleportation of a single-photon state

    NASA Astrophysics Data System (ADS)

    Humble, Travis S.; Bennink, Ryan S.; Grice, Warren P.

    2008-08-01

    Recent demonstrations of teleportation have transferred quantum information encoded into either polarization or fieldquadrature degrees of freedom (DOFs), but an outstanding question is how to simultaneously teleport quantum information encoded into multiple DOFs. We describe how the transverse-spatial, spectral and polarization states of a single photon can be simultaneously teleported using a pair of multimode, polarization-entangled photons derived from spontaneous parametric down-conversion. Furthermore, when the initial photon pair is maximally entangled in the spatial, spectral, and polarization DOFs then the photon's full quantum state can be reliably teleported using a Bell-state measurement based on sum-frequency generation.

  8. Total teleportation of a single-photon state

    SciTech Connect

    Humble, Travis S; Bennink, Ryan S; Grice, Warren P

    2008-01-01

    Recent demonstrations of teleportation have transferred quantum information encoded into either polarization or field-quadrature degrees of freedom (DOFs), but an outstanding question is how to simultaneously teleport quantum information encoded into multiple DOFs. We describe how the transverse-spatial, spectral and polarization states of a single photon can be simultaneously teleported using a pair of multimode, polarization-entangled photons derived from spontaneous parametric down-conversion. Furthermore, when the initial photon pair is maximally entangled in the spatial, spectral, and polarization DOFs then the photon s full quantum state can be reliably teleported using a Bell-state measurement based on sum-frequency generation.

  9. High-speed single-photon signaling for daytime QKD

    NASA Astrophysics Data System (ADS)

    Bienfang, Joshua; Restelli, Alessandro; Clark, Charles

    2011-03-01

    The distribution of quantum-generated cryptographic key at high throughputs can be critically limited by the performance of the systems' single-photon detectors. While noise and afterpulsing are considerations for all single-photon QKD systems, high-transmission rate systems also have critical detector timing-resolution and recovery time requirements. We present experimental results exploiting the high timing resolution and count-rate stability of modified single-photon avalanche diodes (SPADs) in our GHz QKD system operating over a 1.5 km free-space link that demonstrate the ability to apply extremely short temporal gates, enabling daytime free-space QKD with a 4% QBER. We also discuss recent advances in gating techniques for InGaAs SPADs that are suitable for high-speed fiber-based QKD. We present afterpulse-probability measurements that demonstrate the ability to support single-photon count rates above 100 MHz with low afterpulse probability. These results will benefit the design and characterization of free-space and fiber QKD systems. A. Restelli, J.C. Bienfang A. Mink, and C.W. Clark, IEEE J. Sel. Topics in Quant. Electron 16, 1084 (2010).

  10. Efficient generation of indistinguishable single photons on-demand at telecom wavelengths

    NASA Astrophysics Data System (ADS)

    Kim, Jehyung; Cai, Tao; Richardson, Christopher; Leavitt, Richard; Waks, Edo

    Highly efficient single photon sources are important building blocks for optical quantum information processing. For practical use and long-distance quantum communication, single photons should have fiber-compatible telecom wavelengths. In addition, most quantum communication applications require high degree of indistinguishability of single photons, such that they exhibit interference on a beam splitter. However, deterministic generation of indistinguishable single photons with high brightness remains a challenging problem in particular at telecom wavelengths. We demonstrate a telecom wavelength source of indistinguishable single photons using an InAs/InP quantum dot in a nanophotonic cavity. To obtain the efficient single quantum dot emission, we employ the higher order mode in L3 photonic crystal cavity that shows a nearly Gaussian transverse mode profile and results in out-coupling efficiency exceeding 46 % and unusual bright single quantum dot emission exceeding 1.5 million counts per second at a detector. We also observe Purcell enhanced spontaneous emission rate as large as 4 and high linear polarization ratio of 0.96 for the coupled dots. Using this source, we generate high purity single photons at 1.3 μm wavelength and demonstrate the indistinguishable nature of the emission using a two-photon interference measurement.

  11. Heralding Pure Single Photons Generated with Spontaneous Parametric Down Conversion

    NASA Astrophysics Data System (ADS)

    Liu, Xue-lin; Xiang, Tong; Chen, Xian-feng

    2017-09-01

    We investigate the possibility of generated heralding single photons via spontaneous parametric down conversion using periodically poled lithium niobate crystals with different phase-matching. We use the Schmidt decomposition to calculate the degree of entanglement of photon pairs We simulated the spectral purity, bandwidth, and the joint spectral intensity pictures of degenerate and non-degenerate photon pairs. At last, we obtain an ideal condition of the counter-propagating photons, which can be applied in the quantum communication.

  12. Frequency Conversion of Single Photons: Physics, Devices, and Applications

    DTIC Science & Technology

    2012-07-01

    single -photon detector, a schematic of which is shown in Fig. 7.11. To pump both upconversion channels simultaneously, two pump lasers were used. As...112 7.13 Measured single - channel and dual- channel count rates versus input photon flux for two...node (where information is stored and processed ) and an appropriate in- terface by which distant nodes can communicate over a quantum channel . Most

  13. Heralding Pure Single Photons Generated with Spontaneous Parametric Down Conversion

    NASA Astrophysics Data System (ADS)

    Liu, Xue-lin; Xiang, Tong; Chen, Xian-feng

    2017-06-01

    We investigate the possibility of generated heralding single photons via spontaneous parametric down conversion using periodically poled lithium niobate crystals with different phase-matching. We use the Schmidt decomposition to calculate the degree of entanglement of photon pairs We simulated the spectral purity, bandwidth, and the joint spectral intensity pictures of degenerate and non-degenerate photon pairs. At last, we obtain an ideal condition of the counter-propagating photons, which can be applied in the quantum communication.

  14. A single-photon server with just one atom

    NASA Astrophysics Data System (ADS)

    Hijlkema, Markus; Weber, Bernhard; Specht, Holger P.; Webster, Simon C.; Kuhn, Axel; Rempe, Gerhard

    2007-04-01

    Neutral atoms are ideal objects for the deterministic processing of quantum information. Entanglement operations have been carried out by photon exchange or controlled collisions, and atom-photon interfaces have been realized with single atoms in free space or strongly coupled to an optical cavity. A long-standing challenge with neutral atoms, however, is to overcome the limited observation time. Without exception, quantum effects appeared only after ensemble averaging. Here, we report on a single-photon source with one, and only one, atom quasi-permanently coupled to a high-finesse cavity. `Quasi-permanent' refers to our ability to keep the atom long enough to, first, quantify the photon-emission statistics and, second, guarantee the subsequent performance as a single-photon server delivering up to 300,000 photons for up to 30s. This is achieved by a unique combination of single-photon generation and atom cooling. Our scheme brings deterministic protocols of quantum information science with light and matter closer to realization.

  15. Analysis of deterministic swapping of photonic and atomic states through single-photon Raman interaction

    NASA Astrophysics Data System (ADS)

    Rosenblum, Serge; Borne, Adrien; Dayan, Barak

    2017-03-01

    The long-standing goal of deterministic quantum interactions between single photons and single atoms was recently realized in various experiments. Among these, an appealing demonstration relied on single-photon Raman interaction (SPRINT) in a three-level atom coupled to a single-mode waveguide. In essence, the interference-based process of SPRINT deterministically swaps the qubits encoded in a single photon and a single atom, without the need for additional control pulses. It can also be harnessed to construct passive entangling quantum gates, and can therefore form the basis for scalable quantum networks in which communication between the nodes is carried out only by single-photon pulses. Here we present an analytical and numerical study of SPRINT, characterizing its limitations and defining parameters for its optimal operation. Specifically, we study the effect of losses, imperfect polarization, and the presence of multiple excited states. In all cases we discuss strategies for restoring the operation of SPRINT.

  16. Photon statistics of light fields based on single-photon-counting modules

    NASA Astrophysics Data System (ADS)

    Li, G.; Zhang, T. C.; Li, Y.; Wang, J. M.

    2005-02-01

    Single-photon-counting modules (SPCM’s), with their high quantum efficiency, have been widely used to investigate effectively the photon statistics of various light sources, such as the single-photon state and emission light from controlled molecules, atoms, and quantum dots. However, such SPCM’s cannot distinguish the arrivals of one photon and two (or more than two) photons at a moment, which makes measurement correction in real experiments. We analyze the effect of SPCM’s on photon statistics based on the Hanbury-Brown-Twiss configuration when the total efficiency and background are considered, and it shows that the measured second-order degree of coherence and Mandel Q factor for different quantum states, including single-photon states and squeezed vacuum states, are corrected in different forms. A way of determining the squeezing of a squeezed vacuum state based on single-photon detection is presented.

  17. Multiple-Event, Single-Photon Counting Imaging Sensor

    NASA Technical Reports Server (NTRS)

    Zheng, Xinyu; Cunningham, Thomas J.; Sun, Chao; Wang, Kang L.

    2011-01-01

    The single-photon counting imaging sensor is typically an array of silicon Geiger-mode avalanche photodiodes that are monolithically integrated with CMOS (complementary metal oxide semiconductor) readout, signal processing, and addressing circuits located in each pixel and the peripheral area of the chip. The major problem is its single-event method for photon count number registration. A single-event single-photon counting imaging array only allows registration of up to one photon count in each of its pixels during a frame time, i.e., the interval between two successive pixel reset operations. Since the frame time can t be too short, this will lead to very low dynamic range and make the sensor merely useful for very low flux environments. The second problem of the prior technique is a limited fill factor resulting from consumption of chip area by the monolithically integrated CMOS readout in pixels. The resulting low photon collection efficiency will substantially ruin any benefit gained from the very sensitive single-photon counting detection. The single-photon counting imaging sensor developed in this work has a novel multiple-event architecture, which allows each of its pixels to register as more than one million (or more) photon-counting events during a frame time. Because of a consequently boosted dynamic range, the imaging array of the invention is capable of performing single-photon counting under ultra-low light through high-flux environments. On the other hand, since the multiple-event architecture is implemented in a hybrid structure, back-illumination and close-to-unity fill factor can be realized, and maximized quantum efficiency can also be achieved in the detector array.

  18. Manipulation of pulse propagation in a four-level quantum system via an elliptically polarized light in the presence of external magnetic field

    NASA Astrophysics Data System (ADS)

    Karimi, R.; Asadpour, S. H.; Batebi, S.; Soleimani, H. Rahimpour

    2015-10-01

    The influence of external magnetic field and relative phase between two electric field components of the probe field on absorption-dispersion and group index of a four-level atomic system with two degenerate sublevels are investigated. The results show that, the behaviors of weak probe light can be controlled by an external magnetic field. It is shown that in the presence of the external magnetic field the additional electromagnetically induced transparency (EIT) window can be obtained. Our result also reveal that the switching from slow to fast light or vice versa can be manipulated by changing the phase difference between the two circularly polarized components of a single coherent field.

  19. Single-photon multi-ports router based on the coupled cavity optomechanical system

    PubMed Central

    Li, Xun; Zhang, Wen-Zhao; Xiong, Biao; Zhou, Ling

    2016-01-01

    A scheme of single-photon multi-port router is put forward by coupling two optomechanical cavities with waveguides. It is shown that the coupled two optomechanical cavities can exhibit photon blockade effect, which is generated from interference of three mode interaction. A single-photon travel along the system is calculated. The results show that the single photon can be controlled in the multi-port system because of the radiation pressure, which should be useful for constructing quantum network. PMID:28004773

  20. Spin-based single-photon transistor, dynamic random access memory, diodes, and routers in semiconductors

    NASA Astrophysics Data System (ADS)

    Hu, C. Y.

    2016-12-01

    The realization of quantum computers and quantum Internet requires not only quantum gates and quantum memories, but also transistors at single-photon levels to control the flow of information encoded on single photons. Single-photon transistor (SPT) is an optical transistor in the quantum limit, which uses a single photon to open or block a photonic channel. In sharp contrast to all previous SPT proposals which are based on single-photon nonlinearities, here I present a design for a high-gain and high-speed (up to THz) SPT based on a linear optical effect: giant circular birefringence induced by a single spin in a double-sided optical microcavity. A gate photon sets the spin state via projective measurement and controls the light propagation in the optical channel. This spin-cavity transistor can be directly configured as diodes, routers, DRAM units, switches, modulators, etc. Due to the duality as quantum gate and transistor, the spin-cavity unit provides a solid-state platform ideal for future Internet: a mixture of all-optical Internet with quantum Internet.

  1. Single-photon superradiance and radiation trapping by atomic shells

    NASA Astrophysics Data System (ADS)

    Svidzinsky, Anatoly A.; Li, Fu; Li, Hongyuan; Zhang, Xiwen; Ooi, C. H. Raymond; Scully, Marlan O.

    2016-04-01

    The collective nature of light emission by atomic ensembles yields fascinating effects such as superradiance and radiation trapping even at the single-photon level. Light emission is influenced by virtual transitions and the collective Lamb shift which yields peculiar features in temporal evolution of the atomic system. We study how two-dimensional atomic structures collectively emit a single photon. Namely, we consider spherical, cylindrical, and spheroidal shells with two-level atoms continuously distributed on the shell surface and find exact analytical solutions for eigenstates of such systems and their collective decay rates and frequency shifts. We identify states which undergo superradiant decay and states which are trapped and investigate how size and shape of the shell affects collective light emission. Our findings could be useful for quantum information storage and the design of optical switches.

  2. Hyperbolic metamaterial nanoresonators make poor single-photon sources

    NASA Astrophysics Data System (ADS)

    Axelrod, Simon; Dezfouli, Mohsen Kamandar; Wong, Herman M. K.; Helmy, Amr S.; Hughes, Stephen

    2017-04-01

    We study the optical properties of quantum dipole emitters coupled to hyperbolic metamaterial nanoresonators using a semianalytical quasinormal mode approach. We show that coupling to metamaterial nanoresonators can lead to significant Purcell enhancements that are nearly an order of magnitude larger than those of plasmonic resonators with comparable geometry. However, the associated single-photon output β -factors are extremely low (around 10%), far smaller than those of comparably sized metallic resonators (70%). Using a quasinormal mode expansion of the photon Green function, we describe how the low β -factors are due to increased Ohmic quenching arising from redshifted resonances, larger quality factors, and stronger confinement of light within the metal. These results explain why hyperbolic metamaterial nanostructures likely make poor choices for single-photon sources.

  3. Localization of Narrowband Single Photon Emitters in Nanodiamonds.

    PubMed

    Bray, Kerem; Sandstrom, Russell; Elbadawi, Christopher; Fischer, Martin; Schreck, Matthias; Shimoni, Olga; Lobo, Charlene; Toth, Milos; Aharonovich, Igor

    2016-03-23

    Diamond nanocrystals that host room temperature narrowband single photon emitters are highly sought after for applications in nanophotonics and bioimaging. However, current understanding of the origin of these emitters is extremely limited. In this work, we demonstrate that the narrowband emitters are point defects localized at extended morphological defects in individual nanodiamonds. In particular, we show that nanocrystals with defects such as twin boundaries and secondary nucleation sites exhibit narrowband emission that is absent from pristine individual nanocrystals grown under the same conditions. Critically, we prove that the narrowband emission lines vanish when extended defects are removed deterministically using highly localized electron beam induced etching. Our results enhance the current understanding of single photon emitters in diamond and are directly relevant to fabrication of novel quantum optics devices and sensors.

  4. Single-photon nonreciprocal transport in one-dimensional coupled-resonator waveguides

    NASA Astrophysics Data System (ADS)

    Xu, Xun-Wei; Chen, Ai-Xi; Li, Yong; Liu, Yu-xi

    2017-06-01

    We study the transport of a single photon in two coupled one-dimensional semi-infinite coupled-resonator waveguides (CRWs), in which both end sides are coupled to a dissipative cavity. We demonstrate that a single photon can transfer from one semi-infinite CRW to the other nonreciprocally. Based on such nonreciprocity, we further construct a three-port single-photon circulator by a T-shaped waveguide, in which three semi-infinite CRWs are pairwise mutually coupled to each other. The single-photon nonreciprocal transport is induced by the breaking of the time-reversal symmetry and the optimal conditions for these phenomena are obtained analytically. The CRWs with broken time-reversal symmetry will open up a kind of quantum device with versatile applications in quantum networks.

  5. Advanced active quenching circuits for single-photon avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Stipčević, M.; Christensen, B. G.; Kwiat, P. G.; Gauthier, D. J.

    2016-05-01

    Commercial photon-counting modules, often based on actively quenched solid-state avalanche photodiode sensors, are used in wide variety of applications. Manufacturers characterize their detectors by specifying a small set of parameters, such as detection efficiency, dead time, dark counts rate, afterpulsing probability and single photon arrival time resolution (jitter), however they usually do not specify the conditions under which these parameters are constant or present a sufficient description. In this work, we present an in-depth analysis of the active quenching process and identify intrinsic limitations and engineering challenges. Based on that, we investigate the range of validity of the typical parameters used by two commercial detectors. We identify an additional set of imperfections that must be specified in order to sufficiently characterize the behavior of single-photon counting detectors in realistic applications. The additional imperfections include rate-dependence of the dead time, jitter, detection delay shift, and "twilighting." Also, the temporal distribution of afterpulsing and various artifacts of the electronics are important. We find that these additional non-ideal behaviors can lead to unexpected effects or strong deterioration of the system's performance. Specifically, we discuss implications of these new findings in a few applications in which single-photon detectors play a major role: the security of a quantum cryptographic protocol, the quality of single-photon-based random number generators and a few other applications. Finally, we describe an example of an optimized avalanche quenching circuit for a high-rate quantum key distribution system based on time-bin entangled photons.

  6. Controlled single-photon emission from a single trapped two-level atom.

    PubMed

    Darquié, B; Jones, M P A; Dingjan, J; Beugnon, J; Bergamini, S; Sortais, Y; Messin, G; Browaeys, A; Grangier, P

    2005-07-15

    By illuminating an individual rubidium atom stored in a tight optical tweezer with short resonant light pulses, we created an efficient triggered source of single photons with a well-defined polarization. The measured intensity correlation of the emitted light pulses exhibits almost perfect antibunching. Such a source of high-rate, fully controlled single-photon pulses has many potential applications for quantum information processing.

  7. Generation of frequency-multiplexed entangled single photons assisted by entanglement

    SciTech Connect

    Yuan Chunhua; Chen, L. Q.; Zhang Weiping; Ou, Z. Y.

    2011-05-15

    We present a scheme to generate frequency-multiplexed entangled (FME) single photons based on the entanglement between two species in an atomic-mixture ensemble. The atomic ensemble driven by the write and read fields according to a certain timing sequence, the generation of FME single photons can be repeated until success is achieved. The source might have significant applications in wavelength-division-multiplexing quantum key distribution.

  8. Generation of a single-photon source via a four-wave mixing process in a cavity

    SciTech Connect

    Fan Bixuan; Duan Zhenglu; Zhou Lu; Yuan Chunhua; Zhang Weiping; Ou, Z. Y.

    2009-12-15

    It is shown that an efficient, well-directional single-photon source can be realized via a four-wave mixing process in a cavity. The probability of producing a single-photon state nearly approaches 50%. The bandwidth of single-photons generated in this way is controllable, which is determined by that of the input pulse. Furthermore, we propose a scheme to generate a coherent multichannel single-photon source, which might have significant applications in wavelength division multiplexing quantum key distribution.

  9. Special properties of single-photon optical fiber sensor for security needs

    NASA Astrophysics Data System (ADS)

    Zyczkowski, M.; Szustakowski, M.; Karol, M.; Markowski, Piotr; Napierala, M. S.

    2014-10-01

    The rules of quantum physics are now fairly well understood and indisputable. On the basis of these principles are built safety systems to guarantee unconditional security of data transmission. This is possible due to the random behavior of the measured photon. Theorems of quantum mechanics are used currently in Quantum Key Distribution systems to determine the encryption key of cryptographic systems. Sending the single photons through the interferometer it is possible to determine the probability distribution of a photon detection at a given output depending on the interferometer imbalance. The use of single photon interference allows reduce the probability of detection of the transmission line protection. Additionally it provides high safety of transmitted information and minor disturbances. The quantum sensor can be a device which allows effectively protect transmission lines. In this paper we demonstrate measurement results of the using single-photon interferometers in security systems and potential capabilities use of such sensors.

  10. Experimental observation of anomalous trajectories of single photons

    NASA Astrophysics Data System (ADS)

    Zhou, Zong-Quan; Liu, Xiao; Kedem, Yaron; Cui, Jin-Min; Li, Zong-Feng; Hua, Yi-Lin; Li, Chuan-Feng; Guo, Guang-Can

    2017-04-01

    A century after its conception, quantum mechanics still hold surprises that contradict many "common sense" notions. The contradiction is especially sharp in case one consider trajectories of truly quantum objects such as single photons. From a classical point of view, trajectories are well defined for particles, but not for waves. The wave-particle duality forces a breakdown of this dichotomy and quantum mechanics resolves this in a remarkable way: Trajectories can be well defined, but they are utterly different from classical trajectories. Here, we give an operational definition to the trajectory of a single photon by introducing a technique to mark its path using its spectral composition. The method demonstrates that the frequency degree of freedom can be used as a bona fide quantum measurement device (meter). The analysis of a number of setups, using our operational definition, leads to anomalous trajectories which are noncontinuous and in some cases do not even connect the source of the photon to where it is detected. We carried out an experimental demonstration of these anomalous trajectories using a nested interferometer. We show that the two-state vector formalism provides a simple explanation for the results.

  11. Research on high-speed single photon detector

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Yang, Hao; Wang, Di; Ma, Haiqiang; Luo, Kaihong; Sun, Zhibin; Zhai, Guangjie

    2010-10-01

    Single-photon detector based on an InGaAs avalanche photodiode is one of hot research on the quantum photon, and is one of the key technologies on quantum communication and quantum image. It is widely used in applications as high sensitive photon spectrum, high speed optic measurement and so on. A suitable delay and comparator with latch function circuit are used to prevent positive and negative transient pulses from influencing the detection of true photon induced avalanches. A dead time modulation feedback control circuit decreases the after-pulse. Especially, ECL difference circuit is the key of high speed single photon detector. In addition, the detector uses the hot tube fan-cooling method. From the performance test, the lowest temperature reaches -62°C, the minimum gate pulse width is 2ns (Full-Width-Half-Max, FWHM) and the dark counter rate is 2.5×10-6 ns-1 with a detection rate of 10MHz when the quantum efficiency is more than 10%.

  12. SIMULTANEOUS TELEPORTATION OF MULTIPLE SINGLE-PHOTON DEGREES OF FREEDOM

    SciTech Connect

    Humble, Travis S; Bennink, Ryan S; Grice, Warren P

    2011-01-01

    We report how quantum information encoded into multiple photonic degrees of freedom may be simultaneously teleported using a single, common physical process. The application of teleportation to the complete quantum state of a photon, i.e., the spectral, spatial, and polarization component states, permits the full photonic Hilbert space to be used for encoding information while simultaneously enabling subspaces to be addressed individually, e.g., for quantum information processing. We analyze the feasibility of teleporting the full quantum state through numerical analysis of the fidelity under nominal experimental conditions and for different types of input states, e.g., single-photon states that are separable and entangled in the physical degrees of freedom.

  13. Room temperature single photon source using fiber-integrated hexagonal boron nitride

    NASA Astrophysics Data System (ADS)

    Vogl, Tobias; Lu, Yuerui; Lam, Ping Koy

    2017-07-01

    Single photons are a key resource for quantum optics and optical quantum information processing. The integration of scalable room temperature quantum emitters into photonic circuits remains to be a technical challenge. Here we utilize a defect center in hexagonal boron nitride (hBN) attached by Van der Waals force onto a multimode fiber as a single photon source. We perform an optical characterization of the source in terms of spectrum, state lifetime, power saturation and photostability. A special feature of our source is that it allows for easy switching between fiber-coupled and free space single photon generation modes. In order to prove the quantum nature of the emission we measure the second-order correlation function {{g}(2)}≤ft(τ \\right) . For both fiber-coupled and free space emission, the {{g}(2)}≤ft(τ \\right) dips below 0.5 indicating operation in the single photon regime. The results so far demonstrate the feasibility of 2D material single photon sources for scalable photonic quantum information processing.

  14. Single Photon diffraction and interference

    NASA Astrophysics Data System (ADS)

    Hodge, John

    2015-04-01

    A previous paper based on the Scalar Theory of Everything studied photon diffraction and interference (IntellectualArchive, Vol.1, No. 3, P. 20, Toronto, Canada July 2012. http://intellectualarchive.com/?link=item&id=597). Several photons were required in the experiment at the same time. Interference experiments with one photon in the experiment at a time also showed interference patterns. The previous paper with the Bohm Interpretation, models of the screen and mask, and the Transaction Interpretation of Quantum Mechanics were combined. The reverse wave required by the Transaction Interpretation was provided by a reflected plenum wave rather than a reverse time wave. The speed of the plenum wave was assumed to be much faster than the speed of photons/light. Using the assumptions of Fraunhofer diffraction resulted in the same equation for the photon distribution on a screen as the intensity pattern of the Fraunhofer diffraction. (http://myplace.frontier.com/ ~ jchodge/)

  15. Wiring up pre-characterized single-photon emitters by laser lithography

    NASA Astrophysics Data System (ADS)

    Shi, Q.; Sontheimer, B.; Nikolay, N.; Schell, A. W.; Fischer, J.; Naber, A.; Benson, O.; Wegener, M.

    2016-08-01

    Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time.

  16. Wiring up pre-characterized single-photon emitters by laser lithography.

    PubMed

    Shi, Q; Sontheimer, B; Nikolay, N; Schell, A W; Fischer, J; Naber, A; Benson, O; Wegener, M

    2016-08-10

    Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time.

  17. Wiring up pre-characterized single-photon emitters by laser lithography

    PubMed Central

    Shi, Q.; Sontheimer, B.; Nikolay, N.; Schell, A. W.; Fischer, J.; Naber, A.; Benson, O.; Wegener, M.

    2016-01-01

    Future quantum optical chips will likely be hybrid in nature and include many single-photon emitters, waveguides, filters, as well as single-photon detectors. Here, we introduce a scalable optical localization-selection-lithography procedure for wiring up a large number of single-photon emitters via polymeric photonic wire bonds in three dimensions. First, we localize and characterize nitrogen vacancies in nanodiamonds inside a solid photoresist exhibiting low background fluorescence. Next, without intermediate steps and using the same optical instrument, we perform aligned three-dimensional laser lithography. As a proof of concept, we design, fabricate, and characterize three-dimensional functional waveguide elements on an optical chip. Each element consists of one single-photon emitter centered in a crossed-arc waveguide configuration, allowing for integrated optical excitation and efficient background suppression at the same time. PMID:27507165

  18. Efficient concentration protocols for the single-photon entanglement state with polarization feature

    NASA Astrophysics Data System (ADS)

    Zhou, Lan; Wang, Dan-Dan; Wang, Xing-Fu; Gu, Shi-Pu; Sheng, Yu-Bo

    2017-05-01

    We propose two efficient entanglement concentration protocols (ECPs) for arbitrary less-entangled single-photon entanglement state, in which the photon qubit has the polarization feature. The first ECP is in linear optics, and the second ECP is in nonlinear optics. The two ECPs have some attractive advantages. First, they can preserve the polarization feature of the photon qubit, while all the other existing ECPs for single photon state cannot achieve this goal. Second, they only require one pair of less-entangled single-photon entanglement state and some auxiliary single photons. Third, they only require local operations. Especially, the second ECP can be used repeatedly, which can increase its success probability largely. Based on above properties, our two ECPs, especially the second one may be useful in current and future quantum communication.

  19. Design of near-infrared single photon detector at 1550nm wavelength

    NASA Astrophysics Data System (ADS)

    Gao, Jiali

    2016-09-01

    Technology of near-infrared single photon detection is used in quantum communication, laser ranging and weak light detection. Present single photon detectors are usually expensive and bulky. To overcome their disadvantages, a hand-held single photon detector based on InGaAs/InP avalanche photo diode (APD) is developed. A circuit program for temperature control and bias voltage is offered. The gating signal is generated and the avalanche signal is extracted by FPGA. Experiment results show that, the single photon detector yields only 8.2×10-6/ns dark count rate (DCR) when photon detection efficiency is 12%, and the maximum photon detection efficiency of 16% is obtained at temperature of -55°C.

  20. Optical Field-Strength Polarization of Two-Mode Single-Photon States

    ERIC Educational Resources Information Center

    Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

  1. Optical Field-Strength Polarization of Two-Mode Single-Photon States

    ERIC Educational Resources Information Center

    Linares, J.; Nistal, M. C.; Barral, D.; Moreno, V.

    2010-01-01

    We present a quantum analysis of two-mode single-photon states based on the probability distributions of the optical field strength (or position quadrature) in order to describe their quantum polarization characteristics, where polarization is understood as a significative confinement of the optical field-strength values on determined regions of…

  2. Nano-manipulation of diamond-based single photon sources.

    PubMed

    Ampem-Lassen, E; Simpson, D A; Gibson, B C; Trpkovski, S; Hossain, F M; Huntington, S T; Ganesan, K; Hollenberg, L C L; Prawer, S

    2009-07-06

    The ability to manipulate nano-particles at the nano-scale is critical for the development of active quantum systems. This paper presents a technique to manipulate diamond nano-crystals at the nano-scale using a scanning electron microscope, nano-manipulator and custom tapered optical fibre probes. The manipulation of a approximately 300 nm diamond crystal, containing a single nitrogen-vacancy centre, onto the endface of an optical fibre is demonstrated. The emission properties of the single photon source post manipulation are in excellent agreement with those observed on the original substrate.

  3. Operation of silicon single photon avalanche diodes at cryogenic temperature.

    PubMed

    Rech, Ivan; Labanca, Ivan; Armellini, Giacomo; Gulinatti, Angelo; Ghioni, Massimo; Cova, Sergio

    2007-06-01

    This article reports a complete characterization of single photon avalanche diodes (SPADs) at temperatures down to 120 K. We show that deep cooling of the device by means of a compact liquid-nitrogen Dewar brings several advantages, such as extremely low dark counting rates (down to 1 counts/s), better time resolution, and higher quantum efficiency in the visible range. By using a special current pick-off circuit, we achieved a time resolution of 20 ps full width at half maximum at 120 K for a 50 mum diameter SPAD. Afterpulsing effects are avoided by using a sufficiently long hold-off time (microseconds).

  4. Multichannel intensified photodiode for near infrared single photon detection

    NASA Astrophysics Data System (ADS)

    Aebi, Verle W.; Sykora, Derek F.; Jurkovic, Michael J.; Costello, Kenneth A.

    2011-05-01

    An overview of the Intensified Photodiode (IPD) is presented with an emphasis on IPDs optimized for use in the 950nm to 1350nm spectral range for single photon detection applications. The theory of operation of the IPD, two different electron optics designs, and device performance for a multichannel, 4x4 pixel array, low jitter IPD optimized for operation at 1060nm are presented in this paper. Key results include greater than 15% quantum efficiency, large active area, and less than 550ps impulse response.

  5. Single photon detector design features

    NASA Astrophysics Data System (ADS)

    Zaitsev, Sergey V.; Kurochkin, Vladimir L.; Kurochkin, Yury V.

    2016-12-01

    In the report are discussed the laboratory test results of SPAD detectors with InGaAs / InP avalanche photodiodes, operating in Geiger mode. Device operating in synchronous mode with the dead timer setting for proper working conditions of photodiodes. The report materials will showing the functional block diagram of the detector, real operating signals in the receiver path and clock circuits and main results of measurements. The input signal of the synchronous detector is the clock, which determines the time positions of expected photons arrival. Increasing the clock speed 1-300 MHz or getting more time positions of the time grid, we provide increased capacity for time position code of signals, when QKD information transmitted over the nets. At the same time, the maximum attainable speed of photon reception is limited by diode dead time. Diode quantum noise are minimized by inclusion of a special time interval - dead time 0.1-10 usec, after each received and registered a photon. The lowest attainable value of the dead time is determined as a compromise between transients in electrical circuits, passive avalanche «quenching» circuit and thermal transients cooling crystal diode, after each avalanche pass though photodiode. Achievable time and speed parameters are discussed with specific examples of detectors.

  6. Active temporal multiplexing of indistinguishable heralded single photons

    PubMed Central

    Xiong, C.; Zhang, X.; Liu, Z.; Collins, M. J.; Mahendra, A.; Helt, L. G.; Steel, M. J.; Choi, D. -Y.; Chae, C. J.; Leong, P. H. W.; Eggleton, B. J.

    2016-01-01

    It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong–Ou–Mandel quantum interference with a 91±16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies. PMID:26996317

  7. Active temporal multiplexing of indistinguishable heralded single photons

    NASA Astrophysics Data System (ADS)

    Xiong, C.; Zhang, X.; Liu, Z.; Collins, M. J.; Mahendra, A.; Helt, L. G.; Steel, M. J.; Choi, D.-Y.; Chae, C. J.; Leong, P. H. W.; Eggleton, B. J.

    2016-03-01

    It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong-Ou-Mandel quantum interference with a 91+/-16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies.

  8. Cavity-Enhanced Single-Photon Source Based on the Silicon-Vacancy Center in Diamond

    NASA Astrophysics Data System (ADS)

    Benedikter, Julia; Kaupp, Hanno; Hümmer, Thomas; Liang, Yuejiang; Bommer, Alexander; Becher, Christoph; Krueger, Anke; Smith, Jason M.; Hänsch, Theodor W.; Hunger, David

    2017-02-01

    Single-photon sources are an integral part of various quantum technologies, and solid-state quantum emitters at room temperature appear to be a promising implementation. We couple the fluorescence of individual silicon-vacancy centers in nanodiamonds to a tunable optical microcavity to demonstrate a single-photon source with high efficiency, increased emission rate, and improved spectral purity compared to the intrinsic emitter properties. We use a fiber-based microcavity with a mode volume as small as 3.4 λ3 and a quality factor of 1.9 ×1 04 and observe an effective Purcell factor of up to 9.2. Furthermore, we study modifications of the internal rate dynamics and propose a rate model that closely agrees with the measurements. We observe lifetime changes of up to 31%, limited by the finite quantum efficiency of the emitters studied here. With improved materials, our achieved parameters predict single-photon rates beyond 1 GHz.

  9. Design of highly efficient metallo-dielectric patch antennas for single-photon emission.

    PubMed

    Bigourdan, F; Marquier, F; Hugonin, J-P; Greffet, J-J

    2014-02-10

    Quantum emitters such as NV-centers or quantum dots can be used as single-photon sources. To improve their performance, they can be coupled to microcavities or nano-antennas. Plasmonic antennas offer an appealing solution as they can be used with broadband emitters. When properly designed, these antennas funnel light into useful modes, increasing the emission rate and the collection of single-photons. Yet, their inherent metallic losses are responsible for very low radiative efficiencies. Here, we introduce a new design of directional, metallo-dielectric, optical antennas with a Purcell factor of 150, a total efficiency of 74% and a collection efficiency of emitted photons of 99%.

  10. Controlling the interference of single photons emitted by independent atomic sources

    NASA Astrophysics Data System (ADS)

    Cerè, Alessandro; Leong, Victor; Kosen, Sandoko; Srivathsan, Bharath; Gulati, Gurpreet K.; Kurtsiefer, Christian

    2015-09-01

    Hong-Ou-Mandel interference between independent sources is a fundamental primitive of many quantum communication and computation protocols. We present a study of the Hong-Ou-Mandel interference of single photons generated via two different physical processes by two independent atomic systems: scattering by a single atom, and parametric generation via four-wave mixing in a cloud of cold atoms. By controlling the coherence time and central frequency of the heralded single photons generated by four-wave mixing we observe quantum beat and a varying degree of interference.

  11. Monolithic on-chip integration of semiconductor waveguides, beamsplitters and single-photon sources

    NASA Astrophysics Data System (ADS)

    Jöns, Klaus D.; Rengstl, Ulrich; Oster, Markus; Hargart, Fabian; Heldmaier, Matthias; Bounouar, Samir; Ulrich, Sven M.; Jetter, Michael; Michler, Peter

    2015-03-01

    The implementation of fully integrated single-photon sources and detectors into waveguide structures such as photonic crystals or a slab and ridge waveguide is currently one of the major goals in the linear optics quantum computation and communication community. Here, we present an implementation of a single-photon on-chip experiment based on a III-V semiconductor platform. Individual semiconductor quantum dots were used as pulsed single-photon sources integrated in ridge waveguides, and the on-chip waveguide-beamsplitter operation is verified on the single-photon level by performing off-chip photon cross-correlation measurements between the two output ports of the beamsplitter. A degree of polarization of the emitted photons above 90% is observed and a careful characterization of the waveguide propagation losses in straight (< 1.5 dB mm-1) and bent (˜ (8.5 ± 2.2) dB mm-1) sections documents the applicability of such GaAs-based waveguide structures in more complex photonic integrated circuits. The presented work marks an important step towards the realization of fully integrated photonic quantum circuits including on-demand single-photon emitters.

  12. Room-temperature single-photon generation from solitary dopants of carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ma, Xuedan; Hartmann, Nicolai F.; Baldwin, Jon K. S.; Doorn, Stephen K.; Htoon, Han

    2015-08-01

    On-demand single-photon sources capable of operating at room temperature and the telecom wavelength range of 1,300-1,500 nm hold the key to the realization of novel technologies that span from sub-diffraction imaging to quantum key distribution and photonic quantum information processing. Here, we show that incorporation of undoped (6,5) single-walled carbon nanotubes into a SiO2 matrix can lead to the creation of solitary oxygen dopant states capable of fluctuation-free, room-temperature single-photon emission in the 1,100-1,300 nm wavelength range. We investigated the effects of temperature on photoluminescence emission efficiencies, fluctuations and decay dynamics of the dopant states and determined the conditions most suitable for the observation of single-photon emission. This emission can in principle be extended to 1,500 nm by doping of smaller-bandgap single-walled carbon nanotubes. This easy tunability presents a distinct advantage over existing defect centre single-photon emitters (for example, diamond defect centres). Our SiO2-encapsulated sample also presents exciting opportunities to apply Si/SiO2-based micro/nano-device fabrication techniques in the development of electrically driven single-photon sources and integration of these sources into quantum photonic devices and networks.

  13. Improved photon counting efficiency calibration using superconducting single photon detectors

    NASA Astrophysics Data System (ADS)

    Gan, Haiyong; Xu, Nan; Li, Jianwei; Sun, Ruoduan; Feng, Guojin; Wang, Yanfei; Ma, Chong; Lin, Yandong; Zhang, Labao; Kang, Lin; Chen, Jian; Wu, Peiheng

    2015-10-01

    The quantum efficiency of photon counters can be measured with standard uncertainty below 1% level using correlated photon pairs generated through spontaneous parametric down-conversion process. Normally a laser in UV, blue or green wavelength range with sufficient photon energy is applied to produce energy and momentum conserved photon pairs in two channels with desired wavelengths for calibration. One channel is used as the heralding trigger, and the other is used for the calibration of the detector under test. A superconducting nanowire single photon detector with advantages such as high photon counting speed (<20 MHz), low dark count rate (<50 counts per second), and wideband responsivity (UV to near infrared) is used as the trigger detector, enabling correlated photons calibration capabilities into shortwave visible range. For a 355nm single longitudinal mode pump laser, when a superconducting nanowire single photon detector is used as the trigger detector at 1064nm and 1560nm in the near infrared range, the photon counting efficiency calibration capabilities can be realized at 532nm and 460nm. The quantum efficiency measurement on photon counters such as photomultiplier tubes and avalanche photodiodes can be then further extended in a wide wavelength range (e.g. 400-1000nm) using a flat spectral photon flux source to meet the calibration demands in cutting edge low light applications such as time resolved fluorescence and nonlinear optical spectroscopy, super resolution microscopy, deep space observation, and so on.

  14. Tunable and high-purity room temperature single-photon emission from atomic defects in hexagonal boron nitride.

    PubMed

    Grosso, Gabriele; Moon, Hyowon; Lienhard, Benjamin; Ali, Sajid; Efetov, Dmitri K; Furchi, Marco M; Jarillo-Herrero, Pablo; Ford, Michael J; Aharonovich, Igor; Englund, Dirk

    2017-09-26

    Two-dimensional van der Waals materials have emerged as promising platforms for solid-state quantum information processing devices with unusual potential for heterogeneous assembly. Recently, bright and photostable single photon emitters were reported from atomic defects in layered hexagonal boron nitride (hBN), but controlling inhomogeneous spectral distribution and reducing multi-photon emission presented open challenges. Here, we demonstrate that strain control allows spectral tunability of hBN single photon emitters over 6 meV, and material processing sharply improves the single photon purity. We observe high single photon count rates exceeding 7 × 10(6) counts per second at saturation, after correcting for uncorrelated photon background. Furthermore, these emitters are stable to material transfer to other substrates. High-purity and photostable single photon emission at room temperature, together with spectral tunability and transferability, opens the door to scalable integration of high-quality quantum emitters in photonic quantum technologies.Inhomogeneous spectral distribution and multi-photon emission are currently hindering the use of defects in layered hBN as reliable single photon emitters. Here, the authors demonstrate strain-controlled wavelength tuning and increased single photon purity through suitable material processing.

  15. Four-level refrigerator driven by photons

    NASA Astrophysics Data System (ADS)

    Wang, Jianhui; Lai, Yiming; Ye, Zhuolin; He, Jizhou; Ma, Yongli; Liao, Qinghong

    2015-05-01

    We propose a quantum absorption refrigerator driven by photons. The model uses a four-level system as its working substance and couples simultaneously to hot, cold, and solar heat reservoirs. Explicit expressions for the cooling power Q˙c and coefficient of performance (COP) ηCOP are derived, with the purpose of revealing and optimizing the performance of the device. Our model runs most efficiently under the tight coupling condition, and it is consistent with the third law of thermodynamics in the limit T →0 .

  16. Four-level refrigerator driven by photons.

    PubMed

    Wang, Jianhui; Lai, Yiming; Ye, Zhuolin; He, Jizhou; Ma, Yongli; Liao, Qinghong

    2015-05-01

    We propose a quantum absorption refrigerator driven by photons. The model uses a four-level system as its working substance and couples simultaneously to hot, cold, and solar heat reservoirs. Explicit expressions for the cooling power Q̇(c) and coefficient of performance (COP) η(COP) are derived, with the purpose of revealing and optimizing the performance of the device. Our model runs most efficiently under the tight coupling condition, and it is consistent with the third law of thermodynamics in the limit T→0.

  17. Temporal and spatial multiplexed infrared single-photon counter based on high-speed avalanche photodiode

    PubMed Central

    Chen, Xiuliang; Ding, Chengjie; Pan, Haifeng; Huang, Kun; Laurat, Julien; Wu, Guang; Wu, E

    2017-01-01

    We report on a high-speed temporal and spatial multiplexed single-photon counter with photon-number-resolving capability up to four photons. The infrared detector combines a fiber loop to split, delay and recombine optical pulses and a 200 MHz dual-channel single-photon detector based on InGaAs/InP avalanche photodiode. To fully characterize the photon-number-resolving capability, we perform quantum detector tomography and then reconstruct its positive-operator-valued measure and the associated Wigner functions. The result shows that, despite of the afterpulsing noise and limited system detection efficiency, this temporal and spatial multiplexed single-photon counter can already find applications for large repetition rate quantum information schemes. PMID:28294155

  18. Temporal and spatial multiplexed infrared single-photon counter based on high-speed avalanche photodiode

    NASA Astrophysics Data System (ADS)

    Chen, Xiuliang; Ding, Chengjie; Pan, Haifeng; Huang, Kun; Laurat, Julien; Wu, Guang; Wu, E.

    2017-03-01

    We report on a high-speed temporal and spatial multiplexed single-photon counter with photon-number-resolving capability up to four photons. The infrared detector combines a fiber loop to split, delay and recombine optical pulses and a 200 MHz dual-channel single-photon detector based on InGaAs/InP avalanche photodiode. To fully characterize the photon-number-resolving capability, we perform quantum detector tomography and then reconstruct its positive-operator-valued measure and the associated Wigner functions. The result shows that, despite of the afterpulsing noise and limited system detection efficiency, this temporal and spatial multiplexed single-photon counter can already find applications for large repetition rate quantum information schemes.

  19. A universal setup for active control of a single-photon detector.

    PubMed

    Liu, Qin; Lamas-Linares, Antía; Kurtsiefer, Christian; Skaar, Johannes; Makarov, Vadim; Gerhardt, Ilja

    2014-01-01

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.

  20. Time-Bin-Encoded Boson Sampling with a Single-Photon Device.

    PubMed

    He, Yu; Ding, X; Su, Z-E; Huang, H-L; Qin, J; Wang, C; Unsleber, S; Chen, C; Wang, H; He, Y-M; Wang, X-L; Zhang, W-J; Chen, S-J; Schneider, C; Kamp, M; You, L-X; Wang, Z; Höfling, S; Lu, Chao-Yang; Pan, Jian-Wei

    2017-05-12

    Boson sampling is a problem strongly believed to be intractable for classical computers, but can be naturally solved on a specialized photonic quantum simulator. Here, we implement the first time-bin-encoded boson sampling using a highly indistinguishable (∼94%) single-photon source based on a single quantum-dot-micropillar device. The protocol requires only one single-photon source, two detectors, and a loop-based interferometer for an arbitrary number of photons. The single-photon pulse train is time-bin encoded and deterministically injected into an electrically programmable multimode network. The observed three- and four-photon boson sampling rates are 18.8 and 0.2 Hz, respectively, which are more than 100 times faster than previous experiments based on parametric down-conversion.

  1. Time-Bin-Encoded Boson Sampling with a Single-Photon Device

    NASA Astrophysics Data System (ADS)

    He, Yu; Ding, X.; Su, Z.-E.; Huang, H.-L.; Qin, J.; Wang, C.; Unsleber, S.; Chen, C.; Wang, H.; He, Y.-M.; Wang, X.-L.; Zhang, W.-J.; Chen, S.-J.; Schneider, C.; Kamp, M.; You, L.-X.; Wang, Z.; Höfling, S.; Lu, Chao-Yang; Pan, Jian-Wei

    2017-05-01

    Boson sampling is a problem strongly believed to be intractable for classical computers, but can be naturally solved on a specialized photonic quantum simulator. Here, we implement the first time-bin-encoded boson sampling using a highly indistinguishable (˜94 %) single-photon source based on a single quantum-dot-micropillar device. The protocol requires only one single-photon source, two detectors, and a loop-based interferometer for an arbitrary number of photons. The single-photon pulse train is time-bin encoded and deterministically injected into an electrically programmable multimode network. The observed three- and four-photon boson sampling rates are 18.8 and 0.2 Hz, respectively, which are more than 100 times faster than previous experiments based on parametric down-conversion.

  2. A universal setup for active control of a single-photon detector

    NASA Astrophysics Data System (ADS)

    Liu, Qin; Lamas-Linares, Antía; Kurtsiefer, Christian; Skaar, Johannes; Makarov, Vadim; Gerhardt, Ilja

    2014-01-01

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.

  3. A universal setup for active control of a single-photon detector

    SciTech Connect

    Liu, Qin; Skaar, Johannes; Lamas-Linares, Antía; Kurtsiefer, Christian; Makarov, Vadim; Gerhardt, Ilja

    2014-01-15

    The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.

  4. Reading boundless error-free bits using a single photon

    NASA Astrophysics Data System (ADS)

    Guha, Saikat; Shapiro, Jeffrey H.

    2013-06-01

    We address the problem of how efficiently information can be encoded into and read out reliably from a passive reflective surface that encodes classical data by modulating the amplitude and phase of incident light. We show that nature imposes no fundamental upper limit to the number of bits that can be read per expended probe photon and demonstrate the quantum-information-theoretic trade-offs between the photon efficiency (bits per photon) and the encoding efficiency (bits per pixel) of optical reading. We show that with a coherent-state (ideal laser) source, an on-off (amplitude-modulation) pixel encoding, and shot-noise-limited direct detection (an overly optimistic model for commercial CD and DVD drives), the highest photon efficiency achievable in principle is about 0.5 bits read per transmitted photon. We then show that a coherent-state probe can read unlimited bits per photon when the receiver is allowed to make joint (inseparable) measurements on the reflected light from a large block of phase-modulated memory pixels. Finally, we show an example of a spatially entangled nonclassical light probe and a receiver design—constructible using a single-photon source, beam splitters, and single-photon detectors—that can in principle read any number of error-free bits of information. The probe is a single photon prepared in a uniform coherent superposition of multiple orthogonal spatial modes, i.e., a W state. The code and joint-detection receiver complexity required by a coherent-state transmitter to achieve comparable photon efficiency performance is shown to be much higher in comparison to that required by the W-state transceiver, although this advantage rapidly disappears with increasing loss in the system.

  5. SINGLE: single photon sensitive cryogenic light detectors

    NASA Astrophysics Data System (ADS)

    Biassoni, Matteo; SINGLE Collaboration

    2017-09-01

    Thermal detectors operated at few mK as calorimeters are a powerful tool for the study of rare particle physics processes. In order to implement particle identification, light detection can be effectively performed by means of other thermal detectors operated as light sensors. This configuration can be used also in large scale, thousand-channels setups, but the light sensors must be sensitive enough to detect few, possibly a single, photons. The SINGLE project described here aims at producing silicon based, large area devices that can be operated as thermal detectors with single-photon sensitivity, and demonstrate the reliability of the performance, scalability of the production process and integrability with present and next generation cryogenic experiments for the search for rare events.

  6. T-shaped single-photon router.

    PubMed

    Lu, Jing; Wang, Z H; Zhou, Lan

    2015-09-07

    We study the transport properties of a single photon scattered by a two-level system (TLS) in a T-shaped waveguide, which is made of two coupled-resonator waveguides (CRWs)- an infinite CRW and a semi-infinite CRW. The spontaneous emission of the TLS directs single photons from one CRW to the other. Although the transfer rate is different for the wave incident from different CRWs, due to the boundary breaking the translational symmetry, the boundary can enhance the transfer rate found in Phys. Rev. Lett. 111, 103604 (2013) and Phys. Rev. A 89, 013805 (2014), as the transfer rate could be unity for the wave incident from the semi-infinite CRW.

  7. Advantages of gated silicon single photon detectors

    NASA Astrophysics Data System (ADS)

    Legré, Matthieu; Lunghi, Tommaso; Stucki, Damien; Zbinden, Hugo

    2013-05-01

    We present gated silicon single photon detectors based on two commercially available avalanche photodiodes (APDs) and one customised APD from ID Quantique SA. This customised APD is used in a commercially available device called id110. A brief comparison of the two commercial APDs is presented. Then, the charge persistence effect of all of those detectors that occurs just after a strong illumination is shown and discussed.

  8. Single Photon Thermal Ionization of C60

    NASA Astrophysics Data System (ADS)

    Hansen, Klavs; Richter, Robert; Alagia, Michele; Stranges, Stefano; Schio, Luca; Salén, Peter; Yatsyna, Vasyl; Feifel, Raimund; Zhaunerchyk, Vitali

    2017-03-01

    We report on experiments which show that C60 can ionize in an indirect, quasithermal boiloff process after absorption of a single photon. The process involves a large number of incoherently excited valence electrons and yields electron spectra with a Boltzmann distribution with temperatures exceeding 104 K . It is expected to be present for other molecules and clusters with a comparatively large number of valence electrons. The astrophysical consequences are briefly discussed.

  9. Angle sensitive single photon avalanche diode

    SciTech Connect

    Lee, Changhyuk Johnson, Ben Molnar, Alyosha

    2015-06-08

    An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

  10. Angle sensitive single photon avalanche diode

    NASA Astrophysics Data System (ADS)

    Lee, Changhyuk; Johnson, Ben; Molnar, Alyosha

    2015-06-01

    An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

  11. Optical nanoantennas: controlled emission of single photon sources

    NASA Astrophysics Data System (ADS)

    van Hulst, Niek

    2011-03-01

    Nanoscale quantum emitters are key elements in quantum optics and sensing. However, efficient optical excitation and detection of such emitters involves large solid angles, due to their omnidirectional interaction with freely propagating light and due to limits of diffraction. Optical nanoantennas offer both nanoscale localization and efficient interaction. Here we focus on the control of the interaction of single photon emitters (molecules, quantum dots) with radiation through metal nanorod antennas. First a novel analytical model is presented, which shows the continuous evolution of the properties of optical antennas as they become increasingly bound, i.e. plasmonic. The model accurately describes the complete emission process, the radiative decay rate, quantum efficiency, and angular emission, moreover gives a quantitative description of the gradual emergence of sub-radiant, super-radiant, and dark modes. Next we investigate experimentally the coupling of a single quantum dot to a nanorod of increasing length. The angular luminescence of the quantum dot is detected through increasingly higher order antenna modes. Simultaneously the emission is strongly polarized and enhanced. Direct confrontation with theory allows to determine the coupling efficiency of the quantum dot to the antenna. Finally, we present unidirectional emission of a single emitter by coupling to a nanofabricated Yagi-Uda antenna. A quantum dot is placed in the near field of the antenna so that it drives the resonant feed element of the antenna. The resulting quantum-dot luminescence is strongly polarized and highly directed into a narrow forward angular cone. The directionality of the quantum dot can be controlled by tuning the antenna dimensions. Thus our results show the potential of optical antennas to communicate energy to, from, and between nano-emitters. A.G.Curto et al., Science 329, 930 (2010)

  12. Ultralow-Noise Room-Temperature Quantum Memory for Polarization Qubits

    NASA Astrophysics Data System (ADS)

    Namazi, Mehdi; Kupchak, Connor; Jordaan, Bertus; Shahrokhshahi, Reihaneh; Figueroa, Eden

    2017-09-01

    Here, we show an ultralow-noise regime of operation in a simple quantum memory in warm 87Rb atomic vapor. By modeling the quantum dynamics of four-level room-temperature atoms, we achieve fidelities >90 % for single-photon-level polarization qubits, surpassing any classical strategies exploiting the nonunitary memory efficiency. Additionally, we show experimental techniques capable of producing fidelities close to unity. Our results demonstrate the potential of simple, resource-moderate experimental room-temperature quantum devices.

  13. Generation of single photons with highly tunable wave shape from a cold atomic ensemble

    PubMed Central

    Farrera, Pau; Heinze, Georg; Albrecht, Boris; Ho, Melvyn; Chávez, Matías; Teo, Colin; Sangouard, Nicolas; de Riedmatten, Hugues

    2016-01-01

    The generation of ultra-narrowband, pure and storable single photons with widely tunable wave shape is an enabling step toward hybrid quantum networks requiring interconnection of remote disparate quantum systems. It allows interaction of quantum light with several material systems, including photonic quantum memories, single trapped ions and opto-mechanical systems. Previous approaches have offered a limited tuning range of the photon duration of at most one order of magnitude. Here we report on a heralded single photon source with controllable emission time based on a cold atomic ensemble, which can generate photons with temporal durations varying over three orders of magnitude up to 10 μs without a significant change of the readout efficiency. We prove the nonclassicality of the emitted photons, show that they are emitted in a pure state, and demonstrate that ultra-long photons with nonstandard wave shape can be generated, which are ideally suited for several quantum information tasks. PMID:27886166

  14. Generation of single photons with highly tunable wave shape from a cold atomic ensemble

    NASA Astrophysics Data System (ADS)

    Farrera, Pau; Heinze, Georg; Albrecht, Boris; Ho, Melvyn; Chávez, Matías; Teo, Colin; Sangouard, Nicolas; de Riedmatten, Hugues

    2016-11-01

    The generation of ultra-narrowband, pure and storable single photons with widely tunable wave shape is an enabling step toward hybrid quantum networks requiring interconnection of remote disparate quantum systems. It allows interaction of quantum light with several material systems, including photonic quantum memories, single trapped ions and opto-mechanical systems. Previous approaches have offered a limited tuning range of the photon duration of at most one order of magnitude. Here we report on a heralded single photon source with controllable emission time based on a cold atomic ensemble, which can generate photons with temporal durations varying over three orders of magnitude up to 10 μs without a significant change of the readout efficiency. We prove the nonclassicality of the emitted photons, show that they are emitted in a pure state, and demonstrate that ultra-long photons with nonstandard wave shape can be generated, which are ideally suited for several quantum information tasks.

  15. Electroluminescence from localized defects in zinc oxide: toward electrically driven single photon sources at room temperature.

    PubMed

    Choi, Sumin; Berhane, Amanuel M; Gentle, Angus; Ton-That, Cuong; Phillips, Matthew R; Aharonovich, Igor

    2015-03-18

    Single photon sources are required for a wide range of applications in quantum information science, quantum cryptography, and quantum communications. However, the majority of room temperature emitters to date are only excited optically, which limits their proper integration into scalable devices. In this work, we overcome this limitation and present room temperature electrically driven light emission from localized defects in zinc oxide (ZnO) nanoparticles and thin films. The devices emit in the red spectral range and show excellent rectifying behavior. The emission is stable over an extensive period of time, providing an important prerequisite for practical devices. Our results open possibilities for building new ZnO-based quantum integrated devices that incorporate solid-state single photon sources for quantum information technologies.

  16. Gravitationally induced phase shift on a single photon

    NASA Astrophysics Data System (ADS)

    Hilweg, Christopher; Massa, Francesco; Martynov, Denis; Mavalvala, Nergis; Chruściel, Piotr T.; Walther, Philip

    2017-03-01

    The effect of the Earth’s gravitational potential on a quantum wave function has only been observed for massive particles. In this paper we present a scheme to measure a gravitationally induced phase shift on a single photon traveling in a coherent superposition along different paths of an optical fiber interferometer. To create a measurable signal for the interaction between the static gravitational potential and the wave function of the photon, we propose a variant of a conventional Mach–Zehnder interferometer. We show that the predicted relative phase difference of 10‑5 rad is measurable even in the presence of fiber noise, provided additional stabilization techniques are implemented for each arm of a large-scale fiber interferometer. Effects arising from the rotation of the Earth and the material properties of the fibers are analysed. We conclude that optical fiber interferometry is a feasible way to measure the gravitationally induced phase shift on a single-photon wave function, and thus provides a means to corroborate the equivalence of the energy of the photon and its effective gravitational mass.

  17. An on-chip coupled resonator optical waveguide single-photon buffer

    PubMed Central

    Takesue, Hiroki; Matsuda, Nobuyuki; Kuramochi, Eiichi; Munro, William J.; Notomi, Masaya

    2013-01-01

    Integrated quantum optical circuits are now seen as one of the most promising approaches with which to realize single-photon quantum information processing. Many of the core elements for such circuits have been realized, including sources, gates and detectors. However, a significant missing function necessary for photonic quantum information processing on-chip is a buffer, where single photons are stored for a short period of time to facilitate circuit synchronization. Here we report an on-chip single-photon buffer based on coupled resonator optical waveguides (CROW) consisting of 400 high-Q photonic crystal line-defect nanocavities. By using the CROW, a pulsed single photon is successfully buffered for 150 ps with 50-ps tunability while maintaining its non-classical properties. Furthermore, we show that our buffer preserves entanglement by storing and retrieving one photon from a time-bin entangled state. This is a significant step towards an all-optical integrated quantum information processor. PMID:24217422

  18. Demonstration of Einstein-Podolsky-Rosen Steering Using Single-Photon Path Entanglement and Displacement-Based Detection

    NASA Astrophysics Data System (ADS)

    Guerreiro, T.; Monteiro, F.; Martin, A.; Brask, J. B.; Vértesi, T.; Korzh, B.; Caloz, M.; Bussières, F.; Verma, V. B.; Lita, A. E.; Mirin, R. P.; Nam, S. W.; Marsilli, F.; Shaw, M. D.; Gisin, N.; Brunner, N.; Zbinden, H.; Thew, R. T.

    2016-08-01

    We demonstrate the violation of an Einstein-Podolsky-Rosen steering inequality developed for single-photon path entanglement with displacement-based detection. We use a high-rate source of heralded single-photon path-entangled states, combined with high-efficiency superconducting-based detectors, in a scheme that is free of any postselection and thus immune to the detection loophole. This result conclusively demonstrates single-photon entanglement in a one-sided device-independent scenario, and opens the way towards implementations of device-independent quantum technologies within the paradigm of path entanglement.

  19. Single photon emission from deep-level defects in monolayer WS e2

    NASA Astrophysics Data System (ADS)

    Ye, Yanxia; Dou, Xiuming; Ding, Kun; Chen, Yu; Jiang, Desheng; Yang, Fuhua; Sun, Baoquan

    2017-06-01

    We report an efficient method to observe single photon emissions in monolayer WS e2 by applying hydrostatic pressure. The photoluminescence peaks of typical two-dimensional excitons show a nearly identical pressure-induced blueshift, whereas the energy of pressure-induced discrete emission lines (quantum emitters) demonstrates a pressure insensitive behavior. The decay time of these discrete line emissions is approximately 10 ns, which is at least one order longer than the lifetime of the broad localized (L ) excitons. These characteristics lead to a conclusion that the excitons bound to deep-level defects can be responsible for the observed single photon emissions.

  20. Growth of optical-quality anthracene crystals doped with dibenzoterrylene for controlled single photon production

    SciTech Connect

    Major, Kyle D. Lien, Yu-Hung; Polisseni, Claudio; Grandi, Samuele; Kho, Kiang Wei; Clark, Alex S.; Hwang, J.; Hinds, E. A.

    2015-08-15

    Dibenzoterrylene (DBT) molecules within a crystalline anthracene matrix show promise as quantum emitters for controlled, single photon production. We present the design and construction of a chamber in which we reproducibly grow doped anthracene crystals of optical quality that are several mm across and a few μm thick. We demonstrate control of the DBT concentration over the range 6–300 parts per trillion and show that these DBT molecules are stable single-photon emitters. We interpret our data with a simple model that provides some information on the vapour pressure of DBT.

  1. Kinetics of single-photon emission from electrically pumped NV centers in diamond

    NASA Astrophysics Data System (ADS)

    Khramtsov, I. A.; Agio, M.; Fedyanin, D. Yu.

    2017-09-01

    Nitrogen-vacancy centers in diamond are considered to be promising building blocks for emerging quantum technologies. At the same time, practical applications require them to be excited and controlled electrically. However, there is a lack of knowledge about their behavior in electrical driven systems. Here, we introduce a physical model to address the single-photon emission dynamics of electrically pumped NV center in diamond in a quantitative manner and present a detailed study of the single-photon emitting diode based on NV centers.

  2. Efficient routing of single photons by one atom and a microtoroidal cavity.

    PubMed

    Aoki, Takao; Parkins, A S; Alton, D J; Regal, C A; Dayan, Barak; Ostby, E; Vahala, K J; Kimble, H J

    2009-02-27

    Single photons from a coherent input are efficiently redirected to a separate output by way of a fiber-coupled microtoroidal cavity interacting with individual cesium atoms. By operating in an overcoupled regime for the input-output to a tapered fiber, our system functions as a quantum router with high efficiency for photon sorting. Single photons are reflected and excess photons transmitted, as confirmed by observations of photon antibunching (bunching) for the reflected (transmitted) light. Our photon router is robust against large variations of atomic position and input power, with the observed photon antibunching persisting for intracavity photon number 0.03 < or approximately similar n < or approximately similar 0.7.

  3. Subpicosecond hard x-ray streak camera using single-photon counting.

    PubMed

    Enquist, Henrik; Navirian, Hengameh; Nüske, Ralf; von Korff Schmising, Clemens; Jurgilaitis, Andrius; Herzog, Marc; Bargheer, Matias; Sondhauss, Peter; Larsson, Jörgen

    2010-10-01

    We have developed and characterized a hard x-ray accumulating streak camera that achieves subpicosecond time resolution by using single-photon counting. A high repetition rate of 2 kHz was achieved by use of a readout camera with built-in image processing capabilities. The effects of sweep jitter were removed by using a UV timing reference. The use of single-photon counting allows the camera to reach a high quantum efficiency by not limiting the divergence of the photoelectrons.

  4. Statistical analysis of the temporal single-photon response of superconducting nanowire single photon detection

    NASA Astrophysics Data System (ADS)

    He, Yu-Hao; Chao-Lin, Lü; Zhang, Wei-Jun; Zhang, Lu; Wu, Jun-Jie; Chen, Si-Jing; You, Li-Xing; Wang, Zhen

    2015-06-01

    A new method to study the transient detection efficiency (DE) and pulse amplitude of superconducting nanowire single photon detectors (SNSPD) during the current recovery process is proposed — statistically analyzing the single photon response under photon illumination with a high repetition rate. The transient DE results match well with the DEs deduced from the static current dependence of DE combined with the waveform of a single-photon detection event. This proves that static measurement results can be used to analyze the transient current recovery process after a detection event. The results are relevant for understanding the current recovery process of SNSPDs after a detection event and for determining the counting rate of SNSPDs. Project supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No. XDB04010200), the National Basic Research Program of China (Grant No. 2011CBA00202), and the National Natural Science Foundation of China (Grant No. 61401441).

  5. High-visibility nonclassical interference between intrinsically pure heralded single photons and photons from a weak coherent field

    SciTech Connect

    Jin Ruibo; Zhang Jun; Matsuda, Nobuyuki; Mitsumori, Yasuyoshi; Kosaka, Hideo; Edamatsu, Keiichi; Shimizu, Ryosuke

    2011-03-15

    We present an experiment of nonclassical interference between an intrinsically pure heralded single-photon state and a weak coherent state. Our experiment demonstrates that, without the use of bandpass filters, spectrally pure single photons can have high-visibility (89.4{+-}0.5%) interference with photons from a weak coherent field. Our scheme lays the groundwork for future experiments requiring quantum interference between photons in nonclassical states and those in coherent states.

  6. Single-photon transport through a waveguide coupling to a quadratic optomechanical system

    NASA Astrophysics Data System (ADS)

    Qiao, Lei

    2017-07-01

    We study the coherent transport of a single photon, which propagates in a one-dimensional waveguide and is scattered by a quadratic optomechanical system. Our approach, which is based on the Lippmann-Schwinger equation, gives an analytical solution to describe the single-photon transmission and reflection properties. We analyze the transport spectra and find they are not only related to the optomechanical system's energy-level structure, but also dependent on the optomechanical system's inherent parameters. For the existence of atomic degrees of freedom, we get a Rabi-splitting-like or an electromagnetically induced transparency (EIT)-like spectrum, depending on the atom-cavity coupling strength. Here, we focus on the single-photon strong-coupling regime so that single-quantum effects could be seen.

  7. Time-resolved scattering of a single photon by a single atom

    PubMed Central

    Leong, Victor; Seidler, Mathias Alexander; Steiner, Matthias; Cerè, Alessandro; Kurtsiefer, Christian

    2016-01-01

    Scattering of light by matter has been studied extensively in the past. Yet, the most fundamental process, the scattering of a single photon by a single atom, is largely unexplored. One prominent prediction of quantum optics is the deterministic absorption of a travelling photon by a single atom, provided the photon waveform matches spatially and temporally the time-reversed version of a spontaneously emitted photon. Here we experimentally address this prediction and investigate the influence of the photon's temporal profile on the scattering dynamics using a single trapped atom and heralded single photons. In a time-resolved measurement of atomic excitation we find a 56(11)% increase of the peak excitation by photons with an exponentially rising profile compared with a decaying one. However, the overall scattering probability remains unchanged within the experimental uncertainties. Our results demonstrate that envelope tailoring of single photons enables precise control of the photon–atom interaction. PMID:27897173

  8. Demonstration of digital readout circuit for superconducting nanowire single photon detector.

    PubMed

    Ortlepp, T; Hofherr, M; Fritzsch, L; Engert, S; Ilin, K; Rall, D; Toepfer, H; Meyer, H-G; Siegel, M

    2011-09-12

    We demonstrate the transfer of single photon triggered electrical pulses from a superconducting nanowire single photon detector (SNSPD) to a single flux quantum (SFQ) pulse. We describe design and test of a digital SFQ based SNSPD readout circuit and demonstrate its correct operation. Both circuits (SNSPD and SFQ) operate under the same cryogenic conditions and are directly connected by wire bonds. A future integration of the present multi-chip configuration seems feasible because both fabrication process and materials are very similar. In contrast to commonly used semiconductor amplifiers, SFQ circuits combine very low power dissipation (a few microwatts) with very high operation speed, thus enabling count-rates of several gigahertz. The SFQ interface circuit simplifies the SNSPD readout and enables large numbers of detectors for future compact multi-pixel systems with single photon counting resolution. The demonstrated circuit has great potential for scaling the present interface solution to 1,000 detectors by using a single SFQ chip.

  9. Continuous-Wave Single-Photon Transistor Based on a Superconducting Circuit

    NASA Astrophysics Data System (ADS)

    Kyriienko, Oleksandr; Sørensen, Anders S.

    2016-09-01

    We propose a microwave frequency single-photon transistor which can operate under continuous wave probing and represents an efficient single microwave photon detector. It can be realized using an impedance matched system of a three level artificial ladder-type atom coupled to two microwave cavities connected to input-output waveguides. Using a classical drive on the upper transition, we find parameter space where a single photon control pulse incident on one of the cavities can be fully absorbed into hybridized excited states. This subsequently leads to series of quantum jumps in the upper manifold and the appearance of a photon flux leaving the second cavity through a separate input-output port. The proposal does not require time variation of the probe signals, thus corresponding to a passive version of a single-photon transistor. The resulting device is robust to qubit dephasing processes, possesses low dark count rate for large anharmonicity, and can be readily implemented using current technology.

  10. Narrowband high-fidelity all-fibre source of heralded single photons at 1570 nm.

    PubMed

    McMillan, A R; Fulconis, J; Halder, M; Xiong, C; Rarity, J G; Wadsworth, W J

    2009-04-13

    An all-fibre heralded single photon source operating at 1570 nm has been demonstrated. The device generates correlated photon pairs, widely spaced in frequency, through four-wave mixing in a photonic crystal fibre. Separation of the pair photons and narrowband filtering is all achieved in fibre. The output heralded single photon rate was 9.2 x 10(4) per second, with a counts-to-accidentals ratio of 10.4 and a heralding fidelity of 52 %. Furthermore, narrowband filtering ensured that the output single photon state was near time-bandwidth limited with a coherence length of 4 ps. Such a source is well suited to quantum information processing applications.

  11. Time-resolved scattering of a single photon by a single atom.

    PubMed

    Leong, Victor; Seidler, Mathias Alexander; Steiner, Matthias; Cerè, Alessandro; Kurtsiefer, Christian

    2016-11-29

    Scattering of light by matter has been studied extensively in the past. Yet, the most fundamental process, the scattering of a single photon by a single atom, is largely unexplored. One prominent prediction of quantum optics is the deterministic absorption of a travelling photon by a single atom, provided the photon waveform matches spatially and temporally the time-reversed version of a spontaneously emitted photon. Here we experimentally address this prediction and investigate the influence of the photon's temporal profile on the scattering dynamics using a single trapped atom and heralded single photons. In a time-resolved measurement of atomic excitation we find a 56(11)% increase of the peak excitation by photons with an exponentially rising profile compared with a decaying one. However, the overall scattering probability remains unchanged within the experimental uncertainties. Our results demonstrate that envelope tailoring of single photons enables precise control of the photon-atom interaction.

  12. Testing nonlocality of a single photon without a shared reference frame

    NASA Astrophysics Data System (ADS)

    Brask, Jonatan Bohr; Chaves, Rafael; Brunner, Nicolas

    2013-07-01

    The question of testing the nonlocality of a single photon has raised much debate over the last years. The controversy is intimately related to the issue of providing a common reference frame for the observers to perform their local measurements. Here we address this point by presenting a simple scheme for demonstrating the nonlocality of a single photon which does not require a shared reference frame. Specifically, Bell inequality violation can be obtained with certainty with unaligned devices, even if the relative frame fluctuates between each experimental run of the Bell test. Our scheme appears feasible with current technology and may simplify the realization of quantum communication protocols based on single-photon entanglement.

  13. Time-resolved scattering of a single photon by a single atom

    NASA Astrophysics Data System (ADS)

    Leong, Victor; Seidler, Mathias Alexander; Steiner, Matthias; Cerè, Alessandro; Kurtsiefer, Christian

    2016-11-01

    Scattering of light by matter has been studied extensively in the past. Yet, the most fundamental process, the scattering of a single photon by a single atom, is largely unexplored. One prominent prediction of quantum optics is the deterministic absorption of a travelling photon by a single atom, provided the photon waveform matches spatially and temporally the time-reversed version of a spontaneously emitted photon. Here we experimentally address this prediction and investigate the influence of the photon's temporal profile on the scattering dynamics using a single trapped atom and heralded single photons. In a time-resolved measurement of atomic excitation we find a 56(11)% increase of the peak excitation by photons with an exponentially rising profile compared with a decaying one. However, the overall scattering probability remains unchanged within the experimental uncertainties. Our results demonstrate that envelope tailoring of single photons enables precise control of the photon-atom interaction.

  14. Temporal pure single photons generated from time-frequency entangled biphotons

    NASA Astrophysics Data System (ADS)

    Peng, Qian; Gu, Zhejie; Chen, J. F.; Zhang, Weiping

    2016-11-01

    Narrow-band time-frequency entangled biphotons are generated from spontaneous four-wave mixing in cold atom clouds. The coherence time of the entangled biphotons can be extended to sub-microseconds by the slow light effect. The temporal wavefunction of the biphotons can be manipulated through modulating the spectral or spatial mode of the controlling laser beams. Concerning a pair of entangled biphoton and the resulting heralded single photon, it was commonly believed that, time-frequency entanglement damages the temporal purity of the single photon. However, the case is totally different for biphotons with long coherence time which is far beyond the time resolution of single-photondetectors. We demonstrate that, the single photon heralded from these time-frequency entangled biphotons is in a pure temporal state. Therefore, single photons are able to be shaped through the time-frequency entanglement with their partner photons, while the single photons could be found to be still in a pure state and thus useful for quantum information processing and communication technology.

  15. Wigner spectrum and coherent feedback control of continuous-mode single-photon Fock states

    NASA Astrophysics Data System (ADS)

    Dong, Zhiyuan; Cui, Lei; Zhang, Guofeng; Fu, Hongchen

    2016-10-01

    Single photons are very useful resources in quantum information science. In real applications it is often required that the photons have a well-defined spectral (or equivalently temporal) modal structure. For example, a rising exponential pulse is able to fully excite a two-level atom while a Gaussian pulse cannot. This motivates the study of continuous-mode single-photon Fock states. Such states are characterized by a spectral (or temporal) pulse shape. In this paper we investigate the statistical property of continuous-mode single-photon Fock states. Instead of the commonly used normal ordering (Wick order), the tool we proposed is the Wigner spectrum. The Wigner spectrum has two advantages: (1) it allows to study continuous-mode single-photon Fock states in the time domain and frequency domain simultaneously; (2) because it can deal with the Dirac delta function directly, it has the potential to provide more information than the normal ordering where the Dirac delta function is always discarded. We also show how various control methods in particular coherent feedback control can be used to manipulate the pulse shapes of continuous-mode single-photon Fock states.

  16. Pulsed single-photon spectrometer by frequency-to-time mapping using chirped fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Davis, Alex O. C.; Saulnier, Paul M.; Karpiński, Michał; Smith, Brian J.

    2017-05-01

    A fiber-integrated spectrometer for single-photon pulses outside the telecommunications wavelength range based upon frequency-to-time mapping, implemented by chromatic group delay dispersion (GDD), and precise temporally-resolved single-photon counting, is presented. A chirped fiber Bragg grating provides low-loss GDD, mapping the frequency distribution of an input pulse onto the temporal envelope of the output pulse. Time-resolved detection with fast single-photon-counting modules enables monitoring of a wavelength range from 825 nm to 835 nm with nearly uniform efficiency at 55 pm resolution (24 GHz at 830 nm). To demonstrate the versatility of this technique, spectral interference of heralded single photons and the joint spectral intensity distribution of a photon-pair source are measured. This approach to single-photon-level spectral measurements provides a route to realize applications of time-frequency quantum optics at visible and near-infrared wavelengths, where multiple spectral channels must be simultaneously monitored.

  17. Practical single-photon-assisted remote state preparation with non-maximally entanglement

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Huang, Ai-Jun; Sun, Wen-Yang; Shi, Jia-Dong; Ye, Liu

    2016-08-01

    Remote state preparation (RSP) and joint remote state preparation (JRSP) protocols for single-photon states are investigated via linear optical elements with partially entangled states. In our scheme, by choosing two-mode instances from a polarizing beam splitter, only the sender in the communication protocol needs to prepare an ancillary single-photon and operate the entanglement preparation process in order to retrieve an arbitrary single-photon state from a photon pair in partially entangled state. In the case of JRSP, i.e., a canonical model of RSP with multi-party, we consider that the information of the desired state is split into many subsets and in prior maintained by spatially separate parties. Specifically, with the assistance of a single-photon state and a three-photon entangled state, it turns out that an arbitrary single-photon state can be jointly and remotely prepared with certain probability, which is characterized by the coefficients of both the employed entangled state and the target state. Remarkably, our protocol is readily to extend to the case for RSP and JRSP of mixed states with the all optical means. Therefore, our protocol is promising for communicating among optics-based multi-node quantum networks.

  18. Non-blinking single-photon emitters in silica

    NASA Astrophysics Data System (ADS)

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward Van Der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso De Mello

    2016-02-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots.

  19. Non-blinking single-photon emitters in silica

    DOE PAGES

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; ...

    2016-02-19

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters,more » do not blink, and have photoluminescence lifetimes of a few nanoseconds. Furthermore, photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots.« less

  20. Non-blinking single-photon emitters in silica

    SciTech Connect

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso de Mello

    2016-02-19

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Furthermore, photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots.

  1. Non-blinking single-photon emitters in silica

    PubMed Central

    Rabouw, Freddy T.; Cogan, Nicole M. B.; Berends, Anne C.; Stam, Ward van der; Vanmaekelbergh, Daniel; Koenderink, A. Femius; Krauss, Todd D.; Donega, Celso de Mello

    2016-01-01

    Samples for single-emitter spectroscopy are usually prepared by spin-coating a dilute solution of emitters on a microscope cover slip of silicate based glass (such as quartz). Here, we show that both borosilicate glass and quartz contain intrinsic defect colour centres that fluoresce when excited at 532 nm. In a microscope image the defect emission is indistinguishable from spin-coated emitters. The emission spectrum is characterised by multiple peaks with the main peak between 2.05 and 2.20 eV, most likely due to coupling to a silica vibration with an energy that varies between 160 and 180 meV. The defects are single-photon emitters, do not blink, and have photoluminescence lifetimes of a few nanoseconds. Photoluminescence from such defects may previously have been misinterpreted as originating from single nanocrystal quantum dots. PMID:26892489

  2. On-Chip Waveguide Coupling of a Layered Semiconductor Single-Photon Source.

    PubMed

    Tonndorf, Philipp; Del Pozo-Zamudio, Osvaldo; Gruhler, Nico; Kern, Johannes; Schmidt, Robert; Dmitriev, Alexander I; Bakhtinov, Anatoly P; Tartakovskii, Alexander I; Pernice, Wolfram; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf

    2017-09-13

    Fully integrated quantum technology based on photons is in the focus of current research, because of its immense potential concerning performance and scalability. Ideally, the single-photon sources, the processing units, and the photon detectors are all combined on a single chip. Impressive progress has been made for on-chip quantum circuits and on-chip single-photon detection. In contrast, nonclassical light is commonly coupled onto the photonic chip from the outside, because presently only few integrated single-photon sources exist. Here, we present waveguide-coupled single-photon emitters in the layered semiconductor gallium selenide as promising on-chip sources. GaSe crystals with a thickness below 100 nm are placed on Si3N4 rib or slot waveguides, resulting in a modified mode structure efficient for light coupling. Using optical excitation from within the Si3N4 waveguide, we find nonclassicality of generated photons routed on the photonic chip. Thus, our work provides an easy-to-implement and robust light source for integrated quantum technology.

  3. Ultrabright single-photon source on diamond with electrical pumping at room and high temperatures

    NASA Astrophysics Data System (ADS)

    Fedyanin, D. Yu; Agio, M.

    2016-07-01

    The recently demonstrated electroluminescence of color centers in diamond makes them one of the best candidates for room temperature single-photon sources. However, the reported emission rates are far off what can be achieved by state-of-the-art electrically driven epitaxial quantum dots. Since the electroluminescence mechanism has not yet been elucidated, it is not clear to what extent the emission rate can be increased. Here we develop a theoretical framework to study single-photon emission from color centers in diamond under electrical pumping. The proposed model comprises electron and hole trapping and releasing, transitions between the ground and excited states of the color center as well as structural transformations of the center due to carrier trapping. It provides the possibility to predict both the photon emission rate and the wavelength of emitted photons. Self-consistent numerical simulations of the single-photon emitting diode based on the proposed model show that the photon emission rate can be as high as 100 kcounts s-1 at standard conditions. In contrast to most optoelectronic devices, the emission rate steadily increases with the device temperature achieving of more than 100 Mcount s-1 at 500 K, which is highly advantageous for practical applications. These results demonstrate the potential of color centers in diamond as electrically driven non-classical light emitters and provide a foundation for the design and development of single-photon sources for optical quantum computation and quantum communication networks operating at room and higher temperatures.

  4. Single-photon switch: Controllable scattering of photons inside a one-dimensional resonator waveguide

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Gong, Z. R.; Liu, Y. X.; Sun, C. P.; Nori, F.

    2010-03-01

    We analyze the coherent transport of a single photon, which propagates in a one-dimensional coupled-resonator waveguide and is scattered by a controllable two-level system located inside one of the resonators of this waveguide. Our approach, which uses discrete coordinates, unifies low and high energy effective theories for single-photon scattering. We show that the controllable two-level system can behave as a quantum switch for the coherent transport of a single photon. This study may inspire new electro-optical single-photon quantum devices. We also suggest an experimental setup based on superconducting transmission line resonators and qubits. References: L. Zhou, Z.R. Gong, Y.X. Liu, C.P. Sun, F. Nori, Controllable scattering of photons inside a one-dimensional resonator waveguide, Phys. Rev. Lett. 101, 100501 (2008). L. Zhou, H. Dong, Y.X. Liu, C.P. Sun, F. Nori, Quantum super-cavity with atomic mirrors, Phys. Rev. A 78, 063827 (2008).

  5. Twin-photon correlations in single-photon interference

    NASA Astrophysics Data System (ADS)

    Lahiri, Mayukh; Hochrainer, Armin; Lapkiewicz, Radek; Lemos, Gabriela Barreto; Zeilinger, Anton

    2017-07-01

    The measurement of the correlation between two quantum systems or particles has a broad significance in physics and also plays a central role in the fields of quantum optics and quantum information science. We propose a method of measuring the correlation between the transverse momenta of two photons, in which one only needs to detect one of the photons. We show that it is possible to generate a single-photon fringe pattern by using two spatially separated identical biphoton sources. The fringes are similar to the ones observed in a Michelson interferometer and possess certain remarkable properties. A striking feature of the fringes is that although the pattern is obtained by detecting one photon only of each photon pair, the fringes shift due to a change in the optical path traversed by the undetected photon; the shift is characterized by a combination of wavelengths of both photons. Using this method one can, therefore, measure the wavelength of a photon without detecting it. The visibility of the fringes diminishes as the correlation between the transverse momenta of twin photons decreases: visibility is unity for maximum momentum correlation and zero for no momentum correlation. This dependence allows us to determine the momentum correlation between both photons from the visibility of the fringe pattern obtained by detecting one of the photons only. Our method can potentially be generalized to other quantum entities.

  6. High quality GaAs single photon emitters on Si substrate

    SciTech Connect

    Bietti, S.; Sanguinetti, S.; Cavigli, L.; Accanto, N.; Vinattieri, A.; Minari, S.; Abbarchi, M.; Isella, G.; Frigeri, C.

    2013-12-04

    We describe a method for the direct epitaxial growth of a single photon emitter, based on GaAs quantum dots fabricated by droplet epitaxy, working at liquid nitrogen temperatures on Si substrates. The achievement of quantum photon statistics up to T=80 K is directly proved by antibunching in the second order correlation function as measured with a H anbury Brown and Twiss interferometer.

  7. Looking at single photons using hybrid detectors

    NASA Astrophysics Data System (ADS)

    Bergamaschi, A.; Cartier, S.; Dinapoli, R.; Greiffenberg, D.; Jungmann-Smith, J. H.; Mezza, D.; Mozzanica, A.; Schmitt, B.; Shi, X.; Tinti, G.

    2015-01-01

    The SLS detector group develops silicon hybrid detectors for X-ray applications used in synchrotron facilities all over the world. Both microstrip and pixel detectors with either single photon counting or charge integrating read out are being developed. Low noise charge integrating detectors can be operated in single photon regime, i.e. with low fluxes and high frame rates in order to detect on average less than one photon per cluster of 2×2 pixels. In this case, the analog signal read out for each single X-ray provides information about the energy of the photon. Moreover the signal from neighboring channels can be correlated in order to overcome or even take advantage of charge sharing. The linear charge collection model describing microstrip detectors and large pixels is unsuitable for the calibration of small pitch pixel detectors due to the large amount of charge sharing occurring also in the corner region. For this reason, the linear charge collection model is extended to the case of small pixels and tested with monochromatic X-ray data acquired using the 25 μm pitch MÖNCH and the 75 μm pitch JUNGFRAU detectors. The successful outcome of the calibration of the MÖNCH detector is proven by the high energy resolution of the spectrum obtained by accumulating the counts from more than 6000 channels after the correction of the gain mismatches using the proposed model.

  8. Non-classical correlations between single photons and phonons from a mechanical oscillator

    NASA Astrophysics Data System (ADS)

    Riedinger, Ralf; Hong, Sungkun; Norte, Richard A.; Slater, Joshua A.; Shang, Juying; Krause, Alexander G.; Anant, Vikas; Aspelmeyer, Markus; Gröblacher, Simon

    2016-02-01

    Interfacing a single photon with another quantum system is a key capability in modern quantum information science. It allows quantum states of matter, such as spin states of atoms, atomic ensembles or solids, to be prepared and manipulated by photon counting and, in particular, to be distributed over long distances. Such light-matter interfaces have become crucial to fundamental tests of quantum physics and realizations of quantum networks. Here we report non-classical correlations between single photons and phonons—the quanta of mechanical motion—from a nanomechanical resonator. We implement a full quantum protocol involving initialization of the resonator in its quantum ground state of motion and subsequent generation and read-out of correlated photon-phonon pairs. The observed violation of a Cauchy-Schwarz inequality is clear evidence for the non-classical nature of the mechanical state generated. Our results demonstrate the availability of on-chip solid-state mechanical resonators as light-matter quantum interfaces. The performance we achieved will enable studies of macroscopic quantum phenomena as well as applications in quantum communication, as quantum memories and as quantum transducers.

  9. Non-classical correlations between single photons and phonons from a mechanical oscillator.

    PubMed

    Riedinger, Ralf; Hong, Sungkun; Norte, Richard A; Slater, Joshua A; Shang, Juying; Krause, Alexander G; Anant, Vikas; Aspelmeyer, Markus; Gröblacher, Simon

    2016-02-18

    Interfacing a single photon with another quantum system is a key capability in modern quantum information science. It allows quantum states of matter, such as spin states of atoms, atomic ensembles or solids, to be prepared and manipulated by photon counting and, in particular, to be distributed over long distances. Such light-matter interfaces have become crucial to fundamental tests of quantum physics and realizations of quantum networks. Here we report non-classical correlations between single photons and phonons--the quanta of mechanical motion--from a nanomechanical resonator. We implement a full quantum protocol involving initialization of the resonator in its quantum ground state of motion and subsequent generation and read-out of correlated photon-phonon pairs. The observed violation of a Cauchy-Schwarz inequality is clear evidence for the non-classical nature of the mechanical state generated. Our results demonstrate the availability of on-chip solid-state mechanical resonators as light-matter quantum interfaces. The performance we achieved will enable studies of macroscopic quantum phenomena as well as applications in quantum communication, as quantum memories and as quantum transducers.

  10. Delocalized single-photon Dicke states and the Leggett-Garg inequality in solid state systems

    PubMed Central

    Chen, Guang-Yin; Lambert, Neill; Li, Che-Ming; Chen, Yueh-Nan; Nori, Franco

    2012-01-01

    We show how to realize a single-photon Dicke state in a large one-dimensional array of two-level systems, and discuss how to test its quantum properties. The realization of single-photon Dicke states relies on the cooperative nature of the interaction between a field reservoir and an array of two-level-emitters. The resulting dynamics of the delocalized state can display Rabi-like oscillations when the number of two-level emitters exceeds several hundred. In this case, the large array of emitters is essentially behaving like a “mirror-less cavity”. We outline how this might be realized using a multiple-quantum-well structure or a dc-SQUID array coupled to a transmission line, and discuss how the quantum nature of these oscillations could be tested with an extension of the Leggett-Garg inequality. PMID:23162693

  11. Hong-Ou-Mandel Interference Between Triggered And Heralded Single Photons From Separate Atomic Systems

    NASA Astrophysics Data System (ADS)

    Cere, Alessandro; Leong, Victor; Kaur Gulati, Gurpreet; Srivathsan, Bharath; Kosen, Sandoko; Kurtsiefer, Christian

    2015-05-01

    The realization of quantum networks and long distance quantum communication rely on the capability of generating entanglement between separated nodes. We demonstrate the compatibility of two different sources of single photons: a single atom and four-wave mixing in a cold cloud of atoms. The four-wave mixing process in a cloud of cold 87Rb generates photon pairs. The cascade level scheme used ensures the generation of heralded single photons with exponentially decaying temporal envelope. The temporal shape of the heralding photons matches the shape of photons emitted by spontaneous decay but for the shorter coherence time A single 87Rb atom is trapped in an far-off-resonance optical dipole trap and can be excited with high probability using a short (~3 ns) intense pulse of resonant light, emitting a single photon by spontaneous decay. A large numerical aperture lens collects ~4% of the total fluorescence. The heralded and the triggered photons are launched into a Houng-Ou-Mandel interferometer: a symmetrical beam-splitter with outputs connected to single photon detectors. Scanning the relative delay between the two sources we observe the HOM dip with a maximum visibility of 70 +/-4%.

  12. Angular distribution of single-photon superradiance in a dilute and cold atomic ensemble

    NASA Astrophysics Data System (ADS)

    Kuraptsev, A. S.; Sokolov, I. M.; Havey, M. D.

    2017-08-01

    On the basis of a quantum microscopic approach we study the dynamics of the afterglow of a dilute Gaussian atomic ensemble excited by pulsed radiation. Taking into account the vector nature of the electromagnetic field we analyze in detail the angular and polarization distribution of single-photon superradiance of such an ensemble. The dependence of the angular distribution of superradiance on the length of the pulse and its carrier frequency as well as on the size and the shape of the atomic clouds is studied. We show that there is substantial dependence of the superradiant emission on the polarization and the direction of fluorescence. We observe essential peculiarities of superradiance in the region of the forward diffraction zone and in the area of the coherent backscattering cone. We demonstrate that there are directions for which the rate of fluorescence is several times more than the decay rate of the timed-Dicke state. We show also that single-photon superradiance can be excited by incoherent excitation when atomic polarization in the ensemble is absent. Besides a quantum microscopic approach, we analyze single-photon superradiance on the basis of the theory of incoherent multiple scattering in optically thick media (random walk theory). In the case of very short resonant and long nonresonant pulses we derive simple analytical expressions for the decay rate of single-photon superradiance for incoherent fluorescence in an arbitrary direction.

  13. Dynamics of Single-Photon Emission from Electrically Pumped Color Centers

    NASA Astrophysics Data System (ADS)

    Khramtsov, Igor A.; Agio, Mario; Fedyanin, Dmitry Yu.

    2017-08-01

    Low-power, high-speed, and bright electrically driven true single-photon sources, which are able to operate at room temperature, are vital for the practical realization of quantum-communication networks and optical quantum computations. Color centers in semiconductors are currently the best candidates; however, in spite of their intensive study in the past decade, the behavior of color centers in electrically controlled systems is poorly understood. Here we present a physical model and establish a theoretical approach to address single-photon emission dynamics of electrically pumped color centers, which interprets experimental results. We support our analysis with self-consistent numerical simulations of a single-photon emitting diode based on a single nitrogen-vacancy center in diamond and predict the second-order autocorrelation function and other emission characteristics. Our theoretical findings demonstrate remarkable agreement with the experimental results and pave the way to the understanding of single-electron and single-photon processes in semiconductors.

  14. Single-photon transport through an atomic chain coupled to a one-dimensional nanophotonic waveguide

    NASA Astrophysics Data System (ADS)

    Liao, Zeyang; Zeng, Xiaodong; Zhu, Shi-Yao; Zubairy, M. Suhail

    2015-08-01

    We study the dynamics of a single-photon pulse traveling through a linear atomic chain coupled to a one-dimensional (1D) single mode photonic waveguide. We derive a time-dependent dynamical theory for this collective many-body system which allows us to study the real time evolution of the photon transport and the atomic excitations. Our analytical result is consistent with previous numerical calculations when there is only one atom. For an atomic chain, the collective interaction between the atoms mediated by the waveguide mode can significantly change the dynamics of the system. The reflectivity of a photon can be tuned by changing the ratio of coupling strength and the photon linewidth or by changing the number of atoms in the chain. The reflectivity of a single-photon pulse with finite bandwidth can even approach 100 % . The spectrum of the reflected and transmitted photon can also be significantly different from the single-atom case. Many interesting physical phenomena can occur in this system such as the photonic band-gap effects, quantum entanglement generation, Fano-like interference, and superradiant effects. For engineering, this system may serve as a single-photon frequency filter, single-photon modulation, and may find important applications in quantum information.

  15. Detecting single photons: a supramolecular matter?

    PubMed

    Cangiano, Lorenzo; Dell'Orco, Daniele

    2013-01-04

    Rod photoreceptors detect single photons through a tradeoff of light collecting ability, amplification and speed. Key roles are played by rhodopsin (Rh) and transducin (G(t)), whose complex supramolecular organization in outer segment disks begs for a functional interpretation. Here we review past and recent evidence of a temperature-dependence of photon detection by mammalian rods, and link this phenomenon with the putative oligomeric organization of Rh and new ideas on the dynamics of Rh-G(t) interaction. Identifying an electrophysiological correlate of the supramolecular organization of Rh and G(t) may shed light on the evolutionary advantage it confers to night vision. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  16. On-demand semiconductor single-photon source with near-unity indistinguishability.

    PubMed

    He, Yu-Ming; He, Yu; Wei, Yu-Jia; Wu, Dian; Atatüre, Mete; Schneider, Christian; Höfling, Sven; Kamp, Martin; Lu, Chao-Yang; Pan, Jian-Wei

    2013-03-01

    Single-photon sources based on semiconductor quantum dots offer distinct advantages for quantum information, including a scalable solid-state platform, ultrabrightness and interconnectivity with matter qubits. A key prerequisite for their use in optical quantum computing and solid-state networks is a high level of efficiency and indistinguishability. Pulsed resonance fluorescence has been anticipated as the optimum condition for the deterministic generation of high-quality photons with vanishing effects of dephasing. Here, we generate pulsed single photons on demand from a single, microcavity-embedded quantum dot under s-shell excitation with 3 ps laser pulses. The π pulse-excited resonance-fluorescence photons have less than 0.3% background contribution and a vanishing two-photon emission probability. Non-postselective Hong-Ou-Mandel interference between two successively emitted photons is observed with a visibility of 0.97(2), comparable to trapped atoms and ions. Two single photons are further used to implement a high-fidelity quantum controlled-NOT gate.

  17. Single-photon detection using magnesium diboride superconducting nanowires

    NASA Astrophysics Data System (ADS)

    Shibata, H.; Takesue, H.; Honjo, T.; Akazaki, T.; Tokura, Y.

    2010-11-01

    We fabricated 10 nm thick MgB2 nanowires with a width down to 100 nm using the liftoff process. The I-V characteristics of the nanowire show hysteresis and a sharp voltage jump at Ic. Though a 150 nm wide nanowire exhibits the capacity for detecting a single photon at 405 nm wavelength, the nanowire is too wide to detect a single photon at 1560 nm. A 100 nm wide nanowire exhibits the capacity for detecting single photons in the 405-1560 nm wavelength range. This indicates a possible application of MgB2 as a high-performance superconducting nanowire single-photon detector.

  18. High-speed and high-efficiency travelling wave single-photon detectors embedded in nanophotonic circuits

    PubMed Central

    Pernice, W.H.P.; Schuck, C.; Minaeva, O.; Li, M.; Goltsman, G.N.; Sergienko, A.V.; Tang, H.X.

    2012-01-01

    Ultrafast, high-efficiency single-photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. However, imperfect modal matching and finite photon absorption rates have usually limited their maximum attainable detection efficiency. Here we demonstrate superconducting nanowire detectors atop nanophotonic waveguides, which enable a drastic increase of the absorption length for incoming photons. This allows us to achieve high on-chip single-photon detection efficiency up to 91% at telecom wavelengths, repeatable across several fabricated chips. We also observe remarkably low dark count rates without significant compromise of the on-chip detection efficiency. The detectors are fully embedded in scalable silicon photonic circuits and provide ultrashort timing jitter of 18 ps. Exploiting this high temporal resolution, we demonstrate ballistic photon transport in silicon ring resonators. Our direct implementation of a high-performance single-photon detector on chip overcomes a major barrier in integrated quantum photonics. PMID:23271658

  19. Bright single-photon sources in bottom-up tailored nanowires

    PubMed Central

    Reimer, Michael E.; Bulgarini, Gabriele; Akopian, Nika; Hocevar, Moïra; Bavinck, Maaike Bouwes; Verheijen, Marcel A.; Bakkers, Erik P.A.M.; Kouwenhoven, Leo P.; Zwiller, Val

    2012-01-01

    The ability to achieve near-unity light-extraction efficiency is necessary for a truly deterministic single-photon source. The most promising method to reach such high efficiencies is based on embedding single-photon emitters in tapered photonic waveguides defined by top-down etching techniques. However, light-extraction efficiencies in current top-down approaches are limited by fabrication imperfections and etching-induced defects. The efficiency is further tempered by randomly positioned off-axis quantum emitters. Here we present perfectly positioned single quantum dots on the axis of a tailored nanowire waveguide using bottom-up growth. In comparison to quantum dots in nanowires without waveguides, we demonstrate a 24-fold enhancement in the single-photon flux, corresponding to a light-extraction efficiency of 42%. Such high efficiencies in one-dimensional nanowires are promising to transfer quantum information over large distances between remote stationary qubits using flying qubits within the same nanowire p–n junction. PMID:22415828

  20. 1.5 GHz single-photon detection at telecommunication wavelengths using sinusoidally gated InGaAs/InP avalanche photodiode.

    PubMed

    Namekata, Naoto; Adachi, Shunsuke; Inoue, Shuichiro

    2009-04-13

    We report a telecom-band single-photon detector for gigahertz clocked quantum key distribution systems. The single-photon detector is based on a sinusoidally gated InGaAs/InP avalanche photodiode. The gate repetition frequency of the single-photon detector reached 1.5 GHz. A quantum efficiency of 10.8 % at 1550 nm was obtained with a dark count probability per gate of 6.3 x 10(-7) and an afterpulsing probability of 2.8 %. Moreover, the maximum detection rate of the detector is 20 MHz.

  1. Photon correlation in single-photon frequency upconversion.

    PubMed

    Gu, Xiaorong; Huang, Kun; Pan, Haifeng; Wu, E; Zeng, Heping

    2012-01-30

    We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.

  2. Proposal for automated transformations on single-photon multipath qudits

    NASA Astrophysics Data System (ADS)

    Baldijão, R. D.; Borges, G. F.; Marques, B.; Solís-Prosser, M. A.; Neves, L.; Pádua, S.

    2017-09-01

    We propose a method for implementing automated state transformations on single-photon multipath qudits encoded in a one-dimensional transverse spatial domain. It relies on transferring the encoding from this domain to the orthogonal one by applying a spatial phase modulation with diffraction gratings, merging all the initial propagation paths by using a stable interferometric network, and filtering out the unwanted diffraction orders. The automation feature is attained by utilizing a programmable phase-only spatial light modulator (SLM) where properly designed diffraction gratings displayed on its screen will implement the desired transformations, including, among others, projections, permutations, and random operations. We discuss the losses in the process which is, in general, inherently nonunitary. Some examples of transformations are presented and, considering a realistic scenario, we analyze how they will be affected by the pixelated structure of the SLM screen. The method proposed here enables one to implement much more general transformations on multipath qudits than is possible with a SLM alone operating in the diagonal basis of which-path states. Therefore, it will extend the range of applicability for this encoding in high-dimensional quantum information and computing protocols as well as fundamental studies in quantum theory.

  3. Experimental Realization of Efficient, Room Temperature Single-Photon Sources with Definite Circular and Linear Polarizations

    NASA Astrophysics Data System (ADS)

    Boutsidis, Christos

    In this thesis I present experimental demonstrations of room-temperature, single-photon sources with definite linear and circular polarizations. Definite photon polarization increases the efficiency of quantum communication systems. In contrast with cryogenic-temperature single-photon sources based on epitaxial quantum dots requiring expensive MBE and nanofabrication, my method utilizes a mature liquid crystal technology, which I made consistent with single-emitter fluorescence microscopy. The structures I have prepared are planar-aligned cholesteric liquid crystals forming 1-D photonic bandgaps for circularly-polarized light, which were used to achieve definite circularly-polarized fluorescence of single emitters doped in this environment. I also used planar-aligned nematic liquid crystals to align single molecules with linear dipole moments and achieved definite linearly-polarized fluorescence. I used single nanocrystal quantum dots, single nanodiamond color-centers, rare-earth-doped nanocrystals, and single terrylene and DiIC18(3) dye molecules as emitters. For nanocrystal quantum dots I observed circular polarization dissymmetry factors as large as ge = --1.6. In addition, I observed circularly-polarized resonances in the fluorescence of emitters within a cholesteric microcavity, with cavity quality factors of up to Q ˜ 250. I also showed that the fluorescence of DiIC18(3) dye molecules in planar-aligned nematic cells exhibits definite linear polarization, with a degree of polarization of rho = --0.58 +/- 0.03. Distributed Bragg reflectors form another type of microcavity that can be used to realize a single-photon source. I characterized the fluorescence from nanocrystal quantum dots doped in the defect layers of such microcavites, both organic and inorganic. Finally, to demonstrate the single-photon properties of single-emitter-doped cholesteric and nematic liquid crystal structures and distributed Bragg reflector microcavities, I present observations of

  4. Observation of entanglement between a single trapped atom and a single photon

    NASA Astrophysics Data System (ADS)

    Blinov, B. B.; Moehring, D. L.; Duan, L.-M.; Monroe, C.

    2004-03-01

    An outstanding goal in quantum information science is the faithful mapping of quantum information between a stable quantum memory and a reliable quantum communication channel. This would allow, for example, quantum communication over remote distances, quantum teleportation of matter and distributed quantum computing over a `quantum internet'. Because quantum states cannot in general be copied, quantum information can only be distributed in these and other applications by entangling the quantum memory with the communication channel. Here we report quantum entanglement between an ideal quantum memory-represented by a single trapped 111Cd+ ion-and an ideal quantum communication channel, provided by a single photon that is emitted spontaneously from the ion. Appropriate coincidence measurements between the quantum states of the photon polarization and the trapped ion memory are used to verify their entanglement directly. Our direct observation of entanglement between stationary and `flying' qubits is accomplished without using cavity quantum electrodynamic techniques or prepared non-classical light sources. We envision that this source of entanglement may be used for a variety of quantum communication protocols and for seeding large-scale entangled states of trapped ion qubits for scalable quantum computing.

  5. Modulation of single-photon-level wave packets with two-component electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Yang, Sheng-Jun; Bao, Xiao-Hui; Pan, Jian-Wei

    2015-05-01

    Coherent manipulation of single-photon wave packets is essentially important for optical quantum communication and quantum information processing. In this paper, we realize controllable splitting and modulation of single-photon-level pulses by using a tripod-type atomic medium. The adoption of two control beams enable us to store one signal pulse into superposition of two distinct atomic collective excitations. By controlling the time delay between the two control pulses, we observe splitting of a stored wave packet into two temporally distinct modes. By controlling the frequency detuning of the control beams, we observe both temporal and frequency-domain interference of the retrieval signal pulses, which provides a method for pulse modulation and multisplitting of the signal photons.

  6. Single-photon emitters based on NIR color centers in diamond coupled with solid immersion lenses

    NASA Astrophysics Data System (ADS)

    Monticone, D. Gatto; Forneris, J.; Levi, M.; Battiato, A.; Picollo, F.; Olivero, P.; Traina, P.; Moreva, E.; Enrico, E.; Brida, G.; Degiovanni, I. P.; Genovese, M.; Amato, G.; Boarino, L.

    2014-12-01

    Single-photon sources represent a key enabling technology in quantum optics, and single color centers in diamond are a promising platform to serve this purpose, due to their high quantum efficiency and photostability at room temperature. The widely studied nitrogen-vacancy (NV) centers are characterized by several limitations, thus other defects have recently been considered, with a specific focus of centers emitting in the near-infra red (NIR). In the present work, we report on the coupling of native NIR-emitting centers in high-quality single-crystal diamond with solid immersion lens (SIL) structures fabricated by focused ion beam (FIB) lithography. The reported improvements in terms of light collection efficiency make the proposed system an ideal platform for the development of single-photon emitters with appealing photophysical and spectral properties.

  7. Large scale fabrication of nitrogen vacancy-embedded diamond nanostructures for single-photon source applications

    NASA Astrophysics Data System (ADS)

    Jiang, Qianqing; Li, Wuxia; Tang, Chengchun; Chang, Yanchun; Hao, Tingting; Pan, Xinyu; Ye, Haitao; Li, Junjie; Gu, Changzhi

    2016-11-01

    Some color centers in diamond can serve as quantum bits which can be manipulated with microwave pulses and read out with laser, even at room temperature. However, the photon collection efficiency of bulk diamond is greatly reduced by refraction at the diamond/air interface. To address this issue, we fabricated arrays of diamond nanostructures, differing in both diameter and top end shape, with HSQ and Cr as the etching mask materials, aiming toward large scale fabrication of single-photon sources with enhanced collection efficiency made of nitrogen vacancy (NV) embedded diamond. With a mixture of O2 and CHF3 gas plasma, diamond pillars with diameters down to 45 nm were obtained. The top end shape evolution has been represented with a simple model. The tests of size dependent single-photon properties confirmed an improved single-photon collection efficiency enhancement, larger than tenfold, and a mild decrease of decoherence time with decreasing pillar diameter was observed as expected. These results provide useful information for future applications of nanostructured diamond as a single-photon source. Project supported by the National Key Research and Development Plan of China (Grant No. 2016YFA0200402), the National Natural Science Foundation of China (Grants Nos. 11574369, 11574368, 91323304, 11174362, and 51272278), and the FP7 Marie Curie Action (project No. 295208) sponsored by the European Commission.

  8. Dead Time of Single Photon Avalanche Diodes

    NASA Astrophysics Data System (ADS)

    Neri, L.; Tudisco, S.; Musumeci, F.; Scordino, A.; Fallica, G.; Mazzillo, M.; Zimbone, M.

    2011-06-01

    Single Photon Avalanche Diode (SPAD) is the new generation of Geiger-Muller counter device developed in semiconductor technology [S. Privitera et al. Sensors Journal, vol 8 Iss. 8 (2008) 4636; S. Tudisco et al. IEEE Sensors Journal vol 8 ISS 7-8 (2008) 1324; S. Cova et al. Applied Optics 35 (1996) 1956]. Physical dead time model and noise production process has been analyzed and their corrections have been performed [S.H. Lee, R.P. Gardner, M. Jae, Nucl. Instr. and Meth. in Phys. Res. B 263 (2007) 46]. We have been able to extract the real amount of incident photon rate up to 10 7cps using a device with 0.97μs total deadtime. We also developed the equation of the noise count rate vs incoming photon rate, supported by Montecarlo simulation and experimental data. We marked the difference between dark rate and noise count rate, and introduced the noise rate inside the hybrid deadtime equation used for SPAD device.

  9. Fully industrialised single photon avalanche diodes

    NASA Astrophysics Data System (ADS)

    Pellegrini, S.; Rae, B.

    2017-05-01

    Single Photon Avalanche diodes (SPADs) were first realized more than five decades ago[1][1], and have now been industrialized for mass production in the 130 nm CMOS technology node by STMicroelectronics (STM). In this paper we present the latest STM SPAD with an excellent NIR photon detection probability (>5% at 850nm), a dark count rate median of 100 cps at room temperature and a low breakdown voltage of 14.2V. The dead time of the SPAD is approximately 25 ns, leading to a maximum count rate of 40 Mcps. Thanks to the 130 nm gate length of the CMOS technology used and the associated high digital gate density, complex digital signal processing can be implemented allowing fully integrated systems to be realized. The low bias required by the SPAD makes it possible for voltage generation to be achieved on-chip (e.g. charge pumped). We introduce our first generation time-of-flight system (VL6180) based on the STM SPAD technology, which is capable of ranging up to 60 cm in 60 ms. Ranging capabilities and accuracy are measured using a set of moving targets with reflectance of 5%, 17% and 88% in a fully automated test bed. To the best of our knowledge this was the first high volume SPAD-based device. To our knowledge this is the first time details of SPAD performance over production volumes and lifetime have been presented.

  10. Sufficient condition for the mode mismatch of single photons for scalability of the boson-sampling computer

    NASA Astrophysics Data System (ADS)

    Shchesnovich, V. S.

    2014-02-01

    The boson sampler proposed by Aaronson and Arkhipov is a nonuniversal quantum computer, which can serve as evidence against the extended Church-Turing thesis. It samples the probability distribution at the output of a linear unitary optical network with indistinguishable single photons at the input. Four experimental groups have already tested their small-scale prototypes with up to four photons. A boson sampler with a few dozens of single photons is believed to be hard to simulate on a classical computer. For scalability of a realistic boson sampler with current technology it is necessary to know the effect of the photon mode mismatch on its operation. Here a nondeterministic model of the boson sampler is analyzed, which employs partially indistinguishable single photons emitted by identical sources. A sufficient condition on the average mutual fidelity of the single photons is found, which guarantees that the realistic boson sampler outperforms the classical computer. Moreover, the boson-sampler computer with partially indistinguishable single photons is scalable and has more power than classical computers when the single-photon mode mismatch 1- scales as O (N-3/2) with the total number of photons N.

  11. Generation of Fourier-transform-limited heralded single photons

    SciTech Connect

    U'Ren, Alfred B.; Jeronimo-Moreno, Yasser; Garcia-Gracia, Hipolito

    2007-02-15

    In this paper we study the spectral (temporal) properties of heralded single photon wave packets, triggered by the detection of an idler photon in the process of parametric down conversion. The generated single photons are studied within the framework of the chronocyclic Wigner function, from which the single photon spectral width and temporal duration can be computed. We derive specific conditions on the two-photon joint spectral amplitude which result in both pure and Fourier-transform-limited heralded single photons. Likewise, we present specific source geometries which lead to the fulfillment of these conditions and show that one of these geometries leads, for a given pump bandwidth, to the temporally shortest possible heralded single photon wave packets.

  12. Single photon transfer controlled by excitation phase in a two-atom cavity system

    NASA Astrophysics Data System (ADS)

    Xiao Zhou, Chun; Zhang, Rui; Di Guo, Miao; Moiseev, S. A.; Su, Xue Mei

    2017-06-01

    We investigate the quantum interference effect of single photon transfer in a two-atom cavity system caused by the excitation phase. In the proposed system, the two identical atoms are firstly put into a timed state by an external single photon field. During the excitation, the atoms grasp different phases which depend on the spatial position of the atoms. Due to the strong resonant interaction between the atoms and optical cavity mode, the absorbed input photon can be efficiently transferred from the atoms to the cavity mode. We show that photon transfer is sensitive to the quantum interference caused by the excitation phases of atoms. The atomic positions can also determine the coupling constants between the atoms and cavity mode as well as the interatomic dipole-dipole interaction which causes additional interference effects on the quantum transfer. Based on the characteristics of the excitation phase, we find that it is a feasible scheme to generate a long-lived dark state and it could be useful for storage and manipulation of single photon fields by controlling the excitation phase.

  13. Tuneable on-demand single-photon source in the microwave range

    PubMed Central

    Peng, Z. H.; de Graaf, S. E.; Tsai, J. S.; Astafiev, O. V.

    2016-01-01

    An on-demand single-photon source is a key element in a series of prospective quantum technologies and applications. Here we demonstrate the operation of a tuneable on-demand microwave photon source based on a fully controllable superconducting artificial atom strongly coupled to an open-ended transmission line. The atom emits a photon upon excitation by a short microwave π-pulse applied through a control line. The intrinsically limited device efficiency is estimated to be in the range 65–80% in a wide frequency range from 7.75 to 10.5 GHz continuously tuned by an external magnetic field. The actual demonstrated efficiency is also affected by the excited state preparation, which is about 90% in our experiments. The single-photon generation from the single-photon source is additionally confirmed by anti-bunching in the second-order correlation function. The source may have important applications in quantum communication, quantum information processing and sensing. PMID:27545689

  14. Weak-value amplification of the nonlinear effect of a single photon

    NASA Astrophysics Data System (ADS)

    Hallaji, Matin; Feizpour, Amir; Dmochowski, Greg; Sinclair, Josiah; Steinberg, Aephraim M.

    2017-06-01

    In quantum mechanics, the concept of weak measurements allows for the description of a quantum system both in terms of the initial preparation and the final state (post-selection). This paradigm has been extensively studied theoretically and experimentally, but almost all of weak-measurement experiments carried out to date can be understood in terms of the classical (electromagnetic wave) theory of optics. Here, we present a quantum version in which the measurement apparatus deterministically entangles two distinct optical beams. We show that a single photon, when properly post-selected, can have an effect equal to that of eight photons: that is, in a system where a single photon has been calibrated to write a nonlinear phase shift of φo on a probe beam, we measure phase shifts as large as 8φo for appropriately post-selected single photons. This opens up a new regime for the study of entanglement of optical beams, as well as further investigations of the power of weak-value amplification for the measurement of small quantities.

  15. A four-pixel single-photon pulse-position array fabricated from WSi superconducting nanowire single-photon detectors

    SciTech Connect

    Verma, V. B. Horansky, R.; Lita, A. E.; Mirin, R. P.; Nam, S. W.; Marsili, F.; Stern, J. A.; Shaw, M. D.

    2014-02-03

    We demonstrate a scalable readout scheme for an infrared single-photon pulse-position camera consisting of WSi superconducting nanowire single-photon detectors. For an N × N array, only 2 × N wires are required to obtain the position of a detection event. As a proof-of-principle, we show results from a 2 × 2 array.

  16. Waveguide integrated low noise NbTiN nanowire single-photon detectors with milli-Hz dark count rate

    PubMed Central

    Schuck, Carsten; Pernice, Wolfram H. P.; Tang, Hong X.

    2013-01-01

    Superconducting nanowire single-photon detectors are an ideal match for integrated quantum photonic circuits due to their high detection efficiency for telecom wavelength photons. Quantum optical technology also requires single-photon detection with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-photon detectors based on NbTiN thin films patterned directly on top of Si3N4 waveguides. We systematically investigate a large variety of detector designs and characterize their detection noise performance. Milli-Hz dark count rates are demonstrated over the entire operating range of the nanowire detectors which also feature low timing jitter. The ultra-low dark count rate, in combination with the high detection efficiency inherent to our travelling wave detector geometry, gives rise to a measured noise equivalent power at the 10−20 W/Hz1/2 level. PMID:23714696

  17. Single-Photon LIDAR for Vegetation Analysis

    NASA Astrophysics Data System (ADS)

    Rosette, J.; Field, C.; Nelson, R. F.; Decola, P.; Cook, B. D.; Degnan, J. J.

    2011-12-01

    Lidar is now an established and recognised technology which has been widely applied to assist forest inventory, monitoring and management. Small footprint lidar systems produce dense 'point clouds' from intercepted surfaces which, after classification of ground and vegetation returns, can be related to important forest biophysical parameters such as biomass or carbon. Within the context of NASA's Carbon Monitoring System (CMS) initiative (NASA, 2010), the prototype 100 beam, single-photon, scanning lidar, developed by Sigma Space Corporation, USA, is tested to assess the potential of this sensor for vegetation analysis. This emerging lidar technology is currently generally operated at green wavelengths (532 nm) and, like more conventional discrete return NIR lidar sensors, produces point clouds of intercepted surfaces. However, the high pulse repetition rate (20 kHz) and multibeam approach produces an unprecedented measurement rate (up to 2 Million pixels per second) and a correspondingly high point density. Furthermore, the single photon sensitivity enables the technique to be more easily extended to high altitudes and therefore larger swath widths. Additionally, CW diode laser pumping and a low laser pulse energy (6 μJ at 532 nm) favour an extended laser lifetime while the much lower energy per beamlet (~50nJ) ensures eye safety despite operating at a visible wavelength. Furthermore, the short laser pulse duration (0.7ns) allows the surface to be located with high vertical precision. Although the 532 nm green wavelength lies near the peak of the solar output, the spatial and temporal coherence of the surface returns, combined with stringent instrument specifications (small detector field of view and narrow optical band-pass filter), allow solid surfaces to be distinguished from the solar background during daylight operations. However, for extended volumetric scatterers such as tree canopies, some amount of solar noise is likely to be mixed in with valid biomass

  18. Signal acquisition via polarization modulation in single photon sources

    NASA Astrophysics Data System (ADS)

    McDonnell, Mark D.; Flitney, Adrian P.

    2009-12-01

    A simple model system is introduced for demonstrating how a single photon source might be used to transduce classical analog information. The theoretical scheme results in measurements of analog source samples that are (i) quantized in the sense of analog-to-digital conversion and (ii) corrupted by random noise that is solely due to the quantum uncertainty in detecting the polarization state of each photon. This noise is unavoidable if more than 1 bit per sample is to be transmitted and we show how it may be exploited in a manner inspired by suprathreshold stochastic resonance. The system is analyzed information theoretically, as it can be modeled as a noisy optical communication channel, although unlike classical Poisson channels, the detector’s photon statistics are binomial. Previous results on binomial channels are adapted to demonstrate numerically that the classical information capacity, and thus the accuracy of the transduction, increases logarithmically with the square root of the number of photons, N . Although the capacity is shown to be reduced when an additional detector nonideality is present, the logarithmic increase with N remains.

  19. Signal acquisition via polarization modulation in single photon sources.

    PubMed

    McDonnell, Mark D; Flitney, Adrian P

    2009-12-01

    A simple model system is introduced for demonstrating how a single photon source might be used to transduce classical analog information. The theoretical scheme results in measurements of analog source samples that are (i) quantized in the sense of analog-to-digital conversion and (ii) corrupted by random noise that is solely due to the quantum uncertainty in detecting the polarization state of each photon. This noise is unavoidable if more than 1 bit per sample is to be transmitted and we show how it may be exploited in a manner inspired by suprathreshold stochastic resonance. The system is analyzed information theoretically, as it can be modeled as a noisy optical communication channel, although unlike classical Poisson channels, the detector's photon statistics are binomial. Previous results on binomial channels are adapted to demonstrate numerically that the classical information capacity, and thus the accuracy of the transduction, increases logarithmically with the square root of the number of photons, N. Although the capacity is shown to be reduced when an additional detector nonideality is present, the logarithmic increase with N remains.

  20. Stresses in Tungsten Thin Films for Single Photon Detectors

    NASA Astrophysics Data System (ADS)

    Kaatz, Laurna; Lita, Adriana; Balzar, Davor

    2004-10-01

    Tungsten thin films are used both as photon absorbers and thermometers and are considered for the fabrication of Single Photon Detectors with possible application in quantum computing. These applications require operation close to the superconducting transition temperature, Tc, which is ˜15 mK for alpha-W and up to 4 K for beta-W. The addition of an antireflective silicon oxide coating over the thin film increases the efficiency of the detectors, but suppresses the thin film's Tc. The objective of this study was to examine whether the difference in stress values may affect the Tc and phase composition in the thin films. Stresses in tungsten thin films originate from growing process, and from the difference in thermal expansion coefficients of the substrate, thin film, and coating. Stresses were studied by x-ray diffraction (XRD) through the changes in interplanar spacings. The measurements were carried out both on a W thin film sputtered onto a Si substrate, and another sample with an additional silicon oxide capping, at both room and low ( ˜8 K) temperatures. Based on these measurements and calculations, a correlation was established between the Tc and stresses in thin films, which can explain the suppression of the Tc in capped thin films.