Article
Optics
A. Rasputnyi, D. A. Kopylov
Summary: Theoretical study of quantum cascaded up-conversion (CUpC) of parametric down conversion (PDC) in a finite nonlinear crystal is conducted within parametric approximation, highlighting the exact solutions in high-gain regime and the analysis of parametric amplification and oscillating regions for different mode cases. The influence of CUpC on quadrature squeezing of degenerate PDC is also estimated.
Article
Optics
Mikhail Tokman, Yongrui Wang, Qianfan Chen, Leon Shterengas, Alexey Belyanin
Summary: In this study, we propose and design a high-brightness, ultracompact electrically pumped GaSb-based laser source that generates entangled photons through mode-matched intracavity parametric down-conversion of lasing modes. We develop a nonperturbative quantum theory to describe the nonlinear mixing in highly dispersive and dissipative waveguides, taking into account various effects such as modal dispersion, group and phase mismatch, propagation, dissipation, and coupling to noisy reservoirs. Our theory provides analytic expressions for interpreting experimental results and predicting the performance of monolithic quantum photonic systems.
Article
Physics, Multidisciplinary
Zhen-Yang Peng, Ying-Dan Wang
Summary: We investigated the process of polariton conversion in a 3-mode nonlinear optomechanical system and found a higher conversion rate compared to the standard 2-mode system. By adiabatically eliminating the cavity in the large detuned case, we achieved a parametric down-conversion interaction between two phononic polariton modes. The nonlinear interaction can be enhanced by tuning the cavity detuning, which was confirmed through analytical treatment and numerical simulation. This system holds potential applications in nonlinear phononics.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2023)
Article
Physics, Applied
Prajit Dhara, Spencer J. Johnson, Christos N. Gagatsos, Paul G. Kwiat, Saikat Guha
Summary: This paper investigates a cascaded source that performs linear-optical entanglement swap between two SPDC sources to generate a heralded photonic entangled state with higher fidelity. By utilizing the Bell swap as a heralding trigger, a multiplexed source is constructed, which achieves a high-efficiency trade-off between fidelity and success probability despite switching losses and detector noise. However, the fidelity versus success probability trade-off is compromised beyond a threshold of 1.5 dB loss per switch.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
Lisa Arndt, Fabian Hassler
Summary: This letter discusses the phenomenon of discrete time-translation symmetry breaking in periodically driven systems and proposes the use of quantum vacuum fluctuations to induce period multiplication. The authors demonstrate, using a circuit QED setup, that the system exhibits a nonequilibrium phase transition under weak dissipation or strong driving conditions.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Wanli Xing, T. C. Ralph
Summary: We have derived analytical solutions for the Heisenberg evolution under the trilinear parametric Hamiltonian, which are accurate up to second order in the interaction strength and valid for all pump amplitudes. These solutions enable the incorporation of pump depletion effects in the description of optical parametric amplification in experimentally relevant scenarios and provide a rigorous description of the resulting phenomena.
Article
Optics
Cheng Li, Boris Braverman, Girish Kulkarni, Robert W. Boyd
Summary: We investigated the impact of pump coherence on entanglement produced from SPDC in different DOFs. By using a STHI light-emitting diode as the pump, we achieved the generation of polarization entanglement. The measured two-qubit state had a concurrence of 0.531+/-0.006 and a purity of 0.647+/-0.005, which matched well with the predicted values. We found that using a STHI pump reduced the entanglement and purity of the output polarization two-qubit state due to the coupling between spatiotemporal and polarization DOFs.
Article
Physics, Multidisciplinary
Jing Wang, Chun-Hui Zhang, Jing-Yang Liu, Xue-Rui Qian, Jian Li, Qin Wang
Summary: This paper investigates several methods to obtain high-purity single-photon sources using PPKTP or PPLN nonlinear crystals, presents improved schemes for purity enhancement, conducts numerical simulations demonstrating near-perfect purity can be achieved without filters. This work may offer valuable references for the generation and application of high-purity single-photon sources.
Article
Physics, Multidisciplinary
Stefan Krastanov, Hamza Raniwala, Jeffrey Holzgrafe, Kurt Jacobs, Marko Loncar, Matthew J. Reagor, Dirk R. Englund
Summary: Establishing a network among superconducting quantum computers has long been a challenge due to low microwave-optical coupling and added noise. The proposed optical networking protocol offers a more efficient way to connect these devices, breaking the rate-fidelity trade-off and simplifying entanglement generation.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Oliver F. Thomas, Will McCutcheon, Dara P. S. McCutcheon
Summary: The study reveals that increasing the photon generation rate for parametric heralded single photon sources leads to a decrease in interference visibility, even when using number resolving detection. While tight spectral filtering can enhance interference visibility at low powers, it introduces photon number impurity issues that result in decreased interference visibility and heralding efficiency.
Article
Optics
Yang Xu, Sirui Tang, Nicholas Black, Robert w. Boyd
Summary: This study proposes a spatial domain extension of orthogonal optical coding scheme for image information transmission. By utilizing the phase conjugation property of stimulated parametric down-conversion, the encoded image is transferred and restored using encoding and corrective phase masks.
Review
Quantum Science & Technology
Chao Zhang, Yun-Feng Huang, Bi-Heng Liu, Chuan-Feng Li, Guang-Can Guo
Summary: Entangled photon sources, generated through the SPDC process, are essential for photonic quantum information processing. This review article examines different types of SPDC sources suitable for multiphoton experiments, comparing their performance in terms of indistinguishability, collection efficiency, and brightness. Recent advancements in multiplexed heralded single-photon sources are also discussed, which help mitigate the probabilistic nature of the SPDC process.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
Article
Optics
Ying-Qiu He, Dong Ding, Feng-Li Yan, Ting Gao
Summary: This article explores the differences between higher-order parametric down-conversion (PDC) photon states and states involving independent photon pairs, with a focus on third-order PDC photons. By utilizing symmetry detectors and cascading operations, the generation of third-order PDC photons from twin-beam six-photon symmetric states is achieved, showcasing their application in exploring six-mode-photon entangled states with linear optics.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2021)
Article
Physics, Applied
Xiao-Hai Zhan, Shuang Wang, Zhen-Qiu Zhong, Zhen-Qiang Yin, Wei Chen, De-Yong He, Guang-Can Guo, Zheng-Fu Han
Summary: Quantum key distribution (QKD) protocols rely on single photons for key exchange. Heralded single-photon sources (HSPSs) utilizing spontaneous parametric down-conversion (SPDC) are effective in producing high fidelity single photons, especially for long distance applications. While a pulsed laser is commonly used as the pump for HSPS QKD, it has disadvantages compared to a continuous wave (cw) laser in terms of operational stability and practicality. This paper presents a detailed study of the cw-pumped case, including practical imperfections in experimental instruments. The model developed shows that a cw-pumped setup can achieve a significantly longer transmission distance (31% longer) than the fastest pulsed HSPS QKD system currently available, and offers advantages such as higher operational stability and better spectral characteristics.
PHYSICAL REVIEW APPLIED
(2023)
Article
Optics
Qihang Liu, Jung-Tsung Shen
Summary: This study proposes to generate multi-photon Fock states deterministically using superradiant atoms in a chiral waveguide. The explicit forms of the output quantum photonic states and their correlation functions are calculated, and the conditions for the output optical fields to approach the Fock states asymptotically are established.
Article
Optics
Leili Esmaeilifar, Timothy C. Ralph
Summary: The use of a nonlinear optical interferometer for estimating local gravitational acceleration is investigated. A Mach-Zehnder interferometer (MZI) in an optical fountain configuration with a Kerr nonlinear medium in the arms is studied. This configuration allows parameter estimation beyond the standard Heisenberg limit of a linear interferometer. Compared to previous studies, it is argued that this interferometer configuration is better posed and achieves improved precision for similar scale and pump powers.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Joshua J. Guanzon, Matthew S. Winnel, Austin P. Lund, Timothy C. Ralph
Summary: We introduce a linear optical technique that can achieve ideal quantum teleamplification, improving success probability and resource efficiency. We also demonstrate its applications as a loss-tolerant quantum relay for entanglement distribution and distillation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Nidhin Prasannan, Jan Sperling, Benjamin Brecht, Christine Silberhorn
Summary: We report on the nonlinear squeezing effects of polarization states of light achieved by utilizing click-counting measurements and the intrinsic correlations of a polarization-entangled light source. By deriving theoretical bounds for nonlinear Stokes operators and developing an efficient light source and detection system, we experimentally validate our theoretical predictions and demonstrate highly statistically significant nonclassical correlations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
C. H. R. I. S. T. I. A. N. KIEssLER, H. A. U. K. E. Conradi, M. O. R. I. T. Z. Kleinert, V. I. K. T. O. R. Quiring, H. A. R. A. L. D. Herrmann, C. H. R. I. S. T. I. N. E. Silberhorn
Summary: A chip-size fully integrated fiber-coupled heralded single photon source (HSPS) module based on a hybrid integration of a nonlinear lithium niobate waveguide into a polymer board is presented. Photon pairs at 810 nm (signal) and 1550 nm (idler) are generated via parametric down-conversion pumped at 532 nm in the LiNbO3 waveguide. The module has a size of (2 x 1) cm2 and is fully fiber-coupled with one pump input fiber and two output fibers, achieving a heralded second-order correlation function of g(2) h = 0.05 with a heralding efficiency of & eta;h = 3.5% at low pump powers.
Article
Optics
Renato Domeneguetti, Michael Stefszky, Harald Herrmann, Christine Silberhorn, Ulrik L. Andersen, Jonas S. Neergaard-Nielsen, Tobias Gehring
Summary: This study presents a guided setup for single-mode squeezing on integrated titanium-indiffused periodically poled nonlinear resonators. By using single-mode fibers, a continuous-wave laser beam is delivered and the squeezed field is collected, with up to -3.17(9) dB of useful squeezing available in fibers. The generated squeezed light was applied in a fiber-based phase sensing experiment, showing a quantum enhancement in the signal-to-noise ratio of 0.35 dB. The investigation also reveals that photorefraction can cause system instabilities at high powers.
Article
Physics, Multidisciplinary
Federico Pegoraro, Philip Held, Sonja Barkhofen, Benjamin Brecht, Christine Silberhorn
Summary: In real photonic quantum systems, losses limit scalability and application in fields such as quantum information and communication. Efforts have been made to improve particle sources and system components, and post-selection methods have been used to mitigate the effect of losses. However, the impact of losses on the behavior of the surviving subset of a multi-particle system has not been studied.
Article
Optics
Wanli Xing, T. C. Ralph
Summary: We have derived analytical solutions for the Heisenberg evolution under the trilinear parametric Hamiltonian, which are accurate up to second order in the interaction strength and valid for all pump amplitudes. These solutions enable the incorporation of pump depletion effects in the description of optical parametric amplification in experimentally relevant scenarios and provide a rigorous description of the resulting phenomena.
Article
Optics
Caroline Mauron, Timothy C. Ralph
Summary: We analyze and compare three quantum communication protocols proposed in the literature for their ability to transmit single-rail entanglement. Specific metrics are used to measure output-state purity and probability of success, taking into account the imperfections of photon source and detection components. Our findings suggest that, under most conditions, a distributed noiseless linear amplification (NLA) protocol with a relay point placed halfway between Alice and Bob outperforms NLA at Bob's end and a recently proposed purification protocol, unless the distance is very small or the photon source component is of high quality.
Article
Optics
Josephine Dias, Matthew S. Winnel, William J. Munro, T. C. Ralph, Kae Nemoto
Summary: This study presents a method of using a discrete-variable repeater protocol to distribute continuous-variable states and compares the rates of continuous-variable entanglement distribution between first-generation continuous- and discrete-variable quantum repeaters.
Article
Optics
Philip Held, Melanie Engelkemeier, Syamsundar De, Sonja Barkhofen, Jan Sperling, Christine Silberhorn
Summary: This article introduces the concept of a driven Gaussian quantum walk, which describes the walk process using a nonlinear map instead of a unitary operation. This expands the applications of quantum walks by incorporating nonlinear elements into their operation. An entire framework for understanding driven Gaussian quantum walks is developed, including methods for characterizing nonlinear, quantum, and quantum-nonlinear effects. The article compares driven Gaussian quantum walks with their classical counterparts and explores the generation and enhancement of quantum effects during the nonlinear walk. The quantumness of the evolution is proven regardless of the input state. A proposed experimental realization scheme and exploration of nonlinear properties of driven Gaussian quantum walks are also discussed.
Article
Optics
Craig S. Hamilton, Regina Christ, Sonja Barkhofen, Stephen M. Barnett, Igor Jex, Christine Silberhorn
Summary: Many photonic quantum information tasks use single photons and linear transformations for processing information. Integrated optical systems provide useful platforms for these tasks. Nonlinear-waveguide array systems are new technologies that enable multimode quantum operations and can generate highly nonclassical photon states.
Article
Astronomy & Astrophysics
Sho Onoe, Thiago L. M. Guedes, Andrey S. Moskalenko, Alfred Leitenstorfer, Guido Burkard, Timothy C. Ralph
Summary: A new theoretical framework is proposed to describe the experimental advances in electro-optic detection of broadband quantum states. By utilizing concepts from quantum field theory, the nonlinear interaction behind the electro-optic effect is shown to be equivalent to a Unruh-DeWitt detector coupled to a conjugate field. The analysis accurately captures the quantum nature of the vacuum and proposes a specific working regime to experimentally verify the existence of virtual photons with quantum correlations in the electromagnetic ground state.
Article
Optics
Joshua Foo, Sho Onoe, Magdalena Zych, Timothy C. Ralph
Summary: This article presents theoretical models for quantum-optical mode-selective filters and mirrors using continuous-variable teleportation. These devices, known as telefilters and telemirrors, can act as identity channels for specific modes while filtering or reflecting all other modes. The models are used to analyze causality problems in relativistic quantum optics, particularly the transmission and propagation of delocalized wave packets through mode-selective mirrors. The research demonstrates the importance of time delay and considers the discrimination and selection of different modes.
Article
Optics
Nedasadat Hosseinidehaj, Matthew S. Winnel, Timothy C. Ralph
Summary: The continuous-variable quantum key distribution protocol discussed in the text utilizes a bright laser for modulation and self-homodyne detection, resulting in a simpler and more robust approach compared to traditional methods. By properly modulating the squeezed laser and making certain assumptions, the protocol can eliminate information leakage to eavesdroppers and increase tolerance to loss.
Review
Physics, Applied
Emanuele Pelucchi, Giorgos Fagas, Igor Aharonovich, Dirk Englund, Eden Figueroa, Qihuang Gong, Hubel Hannes, Jin Liu, Chao-Yang Lu, Nobuyuki Matsuda, Jian-Wei Pan, Florian Schreck, Fabio Sciarrino, Christine Silberhorn, Jianwei Wang, Klaus D. Jons
Summary: Photonics plays a crucial role in emerging quantum technologies, with its full potential being realized through miniaturization via on-chip integration. Integrated quantum photonics leverages classical integrated photonic technologies for quantum applications and focuses on developing quantum photonic integrated circuits. The Roadmap highlights the value that integrated photonics brings to quantum technologies through specific examples.
NATURE REVIEWS PHYSICS
(2022)