Article
Quantum Science & Technology
Taira Giordani, Valerio Mannucci, Nicolo Spagnolo, Marco Fumero, Arianna Rampini, Emanuele Rodola, Fabio Sciarrino
Summary: Gaussian Boson Sampling (GBS), a non-universal model for quantum computing, has shown faster problem-solving capabilities compared to classical strategies in certain computational models. Recent studies have also identified potential applications beyond sampling tasks. In this work, the authors propose two approaches to benchmark GBS experiments using the distributions of graph feature vectors and graph kernels, demonstrating their effectiveness.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Quantum Science & Technology
Junheng Shi, Tim Byrnes
Summary: This paper investigates Gaussian boson sampling (GBS) with partial distinguishability and proposes a model and algorithm based on virtual modes and indistinguishability efficiency to calculate probabilities. The research provides foundations for probability calculations and offers a method to design sampling algorithms with reduced complexity. The study also reveals the impact of partial distinguishability on the boundary of quantum supremacy in GBS.
NPJ QUANTUM INFORMATION
(2022)
Article
Physics, Multidisciplinary
Han-Sen Zhong, Yu-Hao Deng, Jian Qin, Hui Wang, Ming-Cheng Chen, Li-Chao Peng, Yi-Han Luo, Dian Wu, Si-Qiu Gong, Hao Su, Yi Hu, Peng Hu, Xiao-Yan Yang, Wei-Jun Zhang, Hao Li, Yuxuan Li, Xiao Jiang, Lin Gan, Guangwen Yang, Lixing You, Zhen Wang, Li Li, Nai-Le Liu, Jelmer J. Renema, Chao-Yang Lu, Jian-Wei Pan
Summary: Phase-programmable Gaussian boson sampling (GBS) is a new quantum technology that allows for high-purity and high-efficiency photon sampling through tuning the phase of squeezed input states. The experimental results demonstrate the capability of GBS to pass nonclassicality tests and exhibit nontrivial genuine high-order correlations, indicating robustness against classical simulation schemes.
PHYSICAL REVIEW LETTERS
(2021)
Article
Computer Science, Hardware & Architecture
Sonia Lopez Alarcon, Federico Rueda
Summary: Gaussian boson sampling (GBS) has a strong mathematical connection with combinatorics problems and is applied through a software stack that focuses on high-level description and hardware implementation. This paper describes the general compilation process of GBS and specifically discusses the Strawberry Fields (Xanadu) compilation and simulation framework, including its time profiling and implications on computationally significant problem sizes. Additionally, it presents a compilation step to reduce the complexity of hardware description, resulting in a linear reduction in the overall number of operators as the number of Gaussian operators increases.
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Quantum Science & Technology
Nicolas Quesada, Rachel S. Chadwick, Bryn A. Bell, Juan Miguel Arrazola, Trevor Vincent, Haoyu Qi, Raul Garcia-Patron
Summary: We introduce an algorithm for classical simulation of Gaussian boson sampling that is twice as fast as previously known methods. The complexity of the algorithm is exponential in the number of detected photon pairs and directly proportional to the time required to calculate a probability amplitude for a pure Gaussian state. The main innovation is the use of auxiliary conditioning variables to reduce the problem of sampling to the computation of pure-state probability amplitudes.
Article
Quantum Science & Technology
F. V. Mendes, C. Lima, R. V. Ramos
Summary: This work presents two applications of the Lambert-Tsallis W-q function in quantum photonic Gaussian boson sampling (GBS). Firstly, it shows the possibility of distinguishing between well-functioning and damaged photonic GBS quantum computers by analyzing the randomness of the output data. Secondly, analytical formulas are provided to find the squeezing parameters values when the probability of producing a certain number of photons is known in advance.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Management
Francesco Bova, Avi Goldfarb, Roger G. Melko
Summary: A quantum computer can achieve quantum advantage by performing computations that classical computers cannot. Even without quantum advantage, a quantum computing company may still be more profitable and invest more due to efficiency gains from using quantum algorithms. Additionally, the quantum computing company can become a monopolist even if classical computers can perform certain computations but are not cost-effective enough for commercial viability.
MANAGEMENT SCIENCE
(2022)
Article
Quantum Science & Technology
Ruslan Shaydulin, Stuart Hadfield, Tad Hogg, Ilya Safro
Summary: This study examines the relationship between the Quantum Approximate Optimization Algorithm (QAOA) and the symmetries of the objective function, demonstrating a connection between quantum and classical symmetries. The research explores examples of hard problem classes and shows that classical objective function symmetries can lead to invariant measurement outcome probabilities across different states.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Computer Science, Artificial Intelligence
YaoChong Li, Ri-Gui Zhou, RuiQing Xu, Jia Luo, WenWen Hu, Ping Fan
Summary: This article investigates three graph-theoretic feature selection methods, formulates the problems as quadratic problems in binary variables, and solves them using the quantum approximate optimization algorithm (QAOA). It proposes a method for solving large-scale problems and validates the effectiveness through numerical experiments.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2022)
Article
Optics
Dongmei Han, Na Wang, Meihong Wang, Zhongzhong Qin, Xiaolong Su
Summary: In this study, we experimentally demonstrate the remote preparation and manipulation of squeezed light, verifying the effectiveness of the entanglement-based model and indicating potential applications in remote quantum information processing.
Article
Nanoscience & Nanotechnology
Hamza Jnane, Nicolas P. D. Sawaya, Borja Peropadre, Alan Aspuru-Guzik, Raul Garcia-Patron, Joonsuk Huh
Summary: This work presents a linear optical implementation for analog quantum simulation of molecular vibronic spectra, incorporating non-Condon scattering and small truncation error. By considering non-Condon transitions, the method offers a new way to approximate arbitrary nonunitary operations in quantum simulations. In silico simulations of vibronic spectra for naphthalene, phenanthrene, and benzene were conducted to support the findings.
Article
Physics, Multidisciplinary
Sergey Tarasov, William Shannon, Vladimir Kocharovsky, Vitaly Kocharovsky
Summary: This article introduces the use of a multi-qubit Bose-Einstein condensate (BEC) trap as a platform for studying quantum statistical phenomena in many-body interacting systems. Unlike a linear interferometer, the BEC trap platform is an interacting equilibrium many-body system of atoms. The authors discuss the basic model and main features of this multi-qubit BEC trap.
Article
Physics, Multidisciplinary
Hsien-Yi Hsieh, Yi-Ru Chen, Hsun-Chung Wu, Hua Li Chen, Jingyu Ning, Yao-Chin Huang, Chien-Ming Wu, Ray-Kuang Lee
Summary: This study demonstrates fast, robust quantum state tomography using machine learning, achieving high fidelity reconstruction with a neural network. It also reveals degradation information in low and high noisy scenarios, showcasing the potential of machine learning in quantum state analysis.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Inbar Shani, Emanuele G. Dalla Torre, Michael Stern
Summary: This study theoretically investigates the effects of squeezed states on the coherence properties of spins in the context of hybrid quantum computation. The research finds that while squeezing can enhance the coupling between the resonator and the spin, it also amplifies photon noise and enhances spin decoherence.
Article
Computer Science, Information Systems
Yue Ruan, Zhiqiang Yuan, Xiling Xue, Zhihao Liu
Summary: The Quantum Approximate Optimization Algorithm (QAOA) is an algorithmic framework derived from the Quantum Adiabatic Algorithm (QAA) for finding approximate solutions to combinatorial optimization problems. This paper proposes and discusses several QAOA-based algorithms for solving combinatorial optimization problems with equality and/or inequality constraints. The encoding method for different types of constraints is formalized, and the effectiveness and efficiency of the proposed scheme are demonstrated through examples and results for well-known NP optimization problems. Compared to previous constraint-encoding methods, this work provides a more generalized framework for finding higher-quality approximate solutions to combinatorial problems with various types of constraints in the context of QAOA.
INFORMATION SCIENCES
(2023)
Article
Area Studies
Xuejun Lian, Weiguo Zhang, Yongfang Jia, Yidan Zhu
Summary: This paper uses a remote village in Inner Mongolia as a case study to discuss how coordinated mobilization can establish a temporary grassroots-level emergency order in response to the Covid-19 pandemic. The study finds that the order is established through a combination of state power, villagers' awareness of infection risks, and village self-management traditions. It also reveals that party members, elites, and villagers all make coordinated efforts to mobilize and combat Covid-19.
JOURNAL OF ASIAN PUBLIC POLICY
(2023)
Article
Optics
Dong-hui Fan, Xing-yu Zhang, Wei-jun Zhang, Ruo-yan Ma, Jia-min Xiong, Yu-ze Wang, Zhi-gang Chen, Zhen Wang, Li-xing You
Summary: We propose a method to couple a tapered optical fiber to an inverted tapered SiN waveguide using 3D nanoprinting lithography to fabricate a microfiber. The microfiber, composed of high-refractive-index material, consists of a tapered cladding cap, an S-bend, and a straight part. The simulation shows that our design achieves high coupling efficiency and a wide bandwidth at a specific wavelength.
Article
Optics
Wei Li, Likang Zhang, Hao Tan, Yichen Lu, Sheng-Kai Liao, Jia Huang, Hao Li, Zhen Wang, Hao-Kun Mao, Bingze Yan, Qiong Li, Yang Liu, Qiang Zhang, Cheng-Zhi Peng, Lixing You, Feihu Xu, Jian-Wei Pan
Summary: This article reports a QKD system that can generate keys at a record high rate of 115.8 Mb/s over a 10 km standard optical fiber and distribute keys over up to 328 km of ultralow-loss fiber. These abilities are attributed to a multipixel superconducting nanowire single-photon detector with an ultrahigh counting rate, an integrated transmitter that can stably encode polarization states with low error, a fast post-processing algorithm for generating keys in real time, and the high system clock rate operation. The results demonstrate the feasibility of practical high-rate QKD with photonic techniques, thus opening its possibility for widespread applications.
Article
Optics
Tiancheng Wen, Jia Huang, Jun Huang, Hao Li, Lixing You, Yue Si, Xintong Guo, Liang Zhang, Jianyu Wang
Summary: In high-speed photon-counting communication, the recovery characteristics of superconducting nanowire single photon detectors (SNSPDs) affect both counting and communication performance. A nonlinear detection efficiency recovery model was introduced into the pulse position modulation (PPM) optical communication system based on the SNSPD array, and its impact on counting and communication performance was studied. The results showed that the modified model combined with FEC provided the best decoding performance, especially in scenarios with high PPM order, small array pixel number, and strong noise level.
OPTICS COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Wei Li, Likang Zhang, Yichen Lu, Zheng-Ping Li, Cong Jiang, Yang Liu, Jia Huang, Hao Li, Zhen Wang, Xiang-Bin Wang, Qiang Zhang, Lixing You, Feihu Xu, Jian-Wei Pan
Summary: We propose and demonstrate a new method to achieve twin-field quantum key distribution (TF-QKD) without the need for phase locking. By separating the communication time into reference frames and quantum frames, we establish a global phase reference using the reference frames and reconcile the phase reference efficiently using a tailored algorithm based on fast Fourier transform. We successfully demonstrate no-phase-locking TF-QKD from short to long distances over standard optical fibers, achieving high secret key rates and repeaterlike key rates. Our work provides a scalable and practical solution to TF-QKD, representing an important step towards its wide applications.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Jian Qin, Yu-Hao Deng, Han-Sen Zhong, Li-Chao Peng, Hao Su, Yi-Han Luo, Jia-Min Xu, Dian Wu, Si-Qiu Gong, Hua-Liang Liu, Hui Wang, Ming-Cheng Chen, Li Li, Nai-Le Liu, Chao-Yang Lu, Jian-Wei Pan
Summary: Quantum metrology aims to enhance measurement sensitivity by utilizing quantum resources. We propose and realize a novel quantum metrology scheme that combines unconventional nonlinear interferometers and stimulated emission of squeezed light. Our method achieves a scalable, unconditional, and robust quantum metrological advantage, outperforming ideal 5-N00N states. The demonstrated enhancement in Fisher information per photon, without discounting for imperfections or photon loss, makes our approach applicable in practical quantum metrology at low photon flux regime.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Xue-Mei Gu, Liang Huang, Alejandro Pozas-Kerstjens, Yang-Fan Jiang, Dian Wu, Bing Bai, Qi-Chao Sun, Ming-Cheng Chen, Jun Zhang, Sixia Yu, Qiang Zhang, Chao-Yang Lu, Jian-Wei Pan
Summary: Nonlocality in networks composed of independent sources exhibits different phenomena compared to standard Bell scenarios. Network nonlocality in the entanglement-swapping scenario has been extensively studied, but previous violations of bilocality inequality could not certify the nonclassicality of their sources. We experimentally observe full network nonlocal correlations in a network where the loopholes of source-independence, locality, and measurement-independence are closed. Our experiment violates known inequalities for nonfull network nonlocal correlations by over 5 standard deviations, confirming the absence of classical sources.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Li-Zheng Liu, Yue-Yang Fei, Yingqiu Mao, Yi Hu, Rui Zhang, Xu-Fei Yin, Xiao Jiang, Li Li, Nai-Le Liu, Feihu Xu, Yu-Ao Chen, Jian-Wei Pan
Summary: In this study, a full-period quantum phase estimation approach is proposed and demonstrated. The approach adopts Kitaev's phase estimation algorithm to eliminate phase ambiguity and uses GHZ states to obtain phase values. Through an eight-photon experiment, the estimation of unknown phases in a full period is achieved, and the phase super-resolution and sensitivity beyond the shot-noise limit are observed. This research provides a new way for quantum sensing and represents a solid step towards its general applications.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Chong Ying, Bin Cheng, Youwei Zhao, He-Liang Huang, Yu-Ning Zhang, Ming Gong, Yulin Wu, Shiyu Wang, Futian Liang, Jin Lin, Yu Xu, Hui Deng, Hao Rong, Cheng-Zhi Peng, Man -Hong Yung, Xiaobo Zhu, Jian-Wei Pan
Summary: Although NISQ quantum computing devices are still limited in terms of qubit quantity and quality, quantum computational advantage has been experimentally demonstrated. Hybrid quantum and classical computing architectures have become the main paradigm for exhibiting NISQ applications, with the use of low-depth quantum circuits. This study demonstrates a circuit-cutting method for simulating quantum circuits with multiple logical qubits using only a few physical superconducting qubits, showcasing higher fidelity and scalability.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Yu-Hao Deng, Si-Qiu Gong, Yi-Chao Gu, Zhi-Jiong Zhang, Hua-Liang Liu, Hao Su, Hao-Yang Tang, Jia-Min Xu, Meng-Hao Jia, Ming-Cheng Chen, Han-Sen Zhong, Hui Wang, Jiarong Yan, Yi Hu, Jia Huang, Wei -Jun Zhang, Hao Li, Xiao Jiang, Lixing You, Zhen Wang, Li Li, Nai-Le Liu, Chao -Yang Lu, Jian-Wei Pan
Summary: Gaussian boson sampling (GBS) is a protocol for demonstrating quantum computational advantage and is mathematically associated with graph-related and quantum chemistry problems. This study investigates the enhancement of GBS over classical stochastic algorithms on noisy quantum devices in the computationally interesting regime. Experimental results show the presence of GBS enhancement with a large photon-click number and robustness under certain noise, which may stimulate the development of more efficient classical and quantum-inspired algorithms.
PHYSICAL REVIEW LETTERS
(2023)
Article
Instruments & Instrumentation
Chao Yu, Tianyi Li, Xian-Song Zhao, Hai Lu, Rong Zhang, Feihu Xu, Jun Zhang, Jian-Wei Pan
Summary: In this study, a 4H-SiC single-photon avalanche diode (SPAD) based free-running ultraviolet single-photon detector (UVSPD) with ultralow afterpulse probability is reported. A beveled mesa structure is designed and fabricated for the 4H-SiC SPAD, which shows the characteristic of ultralow dark current. A readout circuit of passive quenching and active reset with a tunable hold-off time setting is further developed to significantly suppress the afterpulsing effect. The nonuniformity of photon detection efficiency (PDE) across the SPAD active area is investigated for performance optimization. The compact UVSPD shows a PDE of 10.3%, a dark count rate of 133 kcps, and an afterpulse probability of 0.3% at 266 nm, indicating its potential for practical ultraviolet photon-counting applications.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Physics, Applied
Mengting Si, Liping Zhou, Wei Peng, Xingyu Zhang, Ailun Yi, Chengli Wang, Hourong Zhou, Zhen Wang, Xin Ou, Lixing You
Summary: This study investigates the method and results of achieving high-efficiency superconducting nanowire single-photon detection on SiC substrates. By depositing polycrystalline NbN thin films onto 4H-SiC substrates and ensuring a flat surface, saturated quantum efficiency covering a wide wavelength range was achieved.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Hao Li, Han Cai, Joseph Forman, Ran Cheng, George Hughes, Harrison Walker, Michael C. Hamilton, Lei Chen, Weijun Zhang, Lixing You, Shane A. Cybart
Summary: By irradiating ultra-thin film NbN microbridges with a focused helium ion beam, the electrical transport properties were studied. It was found that irradiation can modify the critical temperature of NbN, enabling possibilities for superconducting logic circuits and higher-speed and high temperature applications.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Review
Optics
Wei Luo, Lin Cao, Yuzhi Shi, Lingxiao Wan, Hui Zhang, Shuyi Li, Guanyu Chen, Yuan Li, Sijin Li, Yunxiang Wang, Shihai Sun, Muhammad Faeyz Karim, Hong Cai, Leong Chuan Kwek, Ai Qun Liu
Summary: Recent years have seen significant progress in quantum communication and quantum internet through the use of quantum photonic chips, which offer scalability, stability, and low cost in a compact form. This article provides an overview of the advancements in quantum photonic chips for quantum communication, including the main fabrication platforms and key components. It discusses various applications such as quantum key distribution and quantum teleportation. The article also highlights the challenges for achieving high-performance chip-based quantum communication and provides insights into future opportunities for integrated quantum networks.
LIGHT-SCIENCE & APPLICATIONS
(2023)
