检索结果-南通市图书馆

Effect of electromagnetic disturbance on the practical QKD system in the smart grid

在线全文

学校读者我要写书评

暂无评论

chinese physics B 2014年第12期23卷 177-181页

作者：李芳毅王东王双李默银振强李宏伟陈巍韩正甫 Key Laboratory of quantum information University of Science and Technology of ChinaChinese Academy of Sciences synergetic innovation Center of quantum information and quantum physics University of Science and Technology of China

To improve the security of the smart grid, quantum key distribution（QKD） is an excellent choice. The rapid fluctuations on the power aerial optical cable and electromagnetic disturbance in substations are two main challenges for implementation of QKD. Due to insensitivity to birefringence of the channel, the stable phase-coding Faraday–Michelson QKD system is very practical in the smart grid. However, the electromagnetic disturbance in substations on this practical QKD system should be considered. The disturbance might change the rotation angle of the Faraday mirror, and would introduce an additional quantum bit error rate（QBER）. We derive the new fringe visibility of the system and the additional QBER from the electromagnetic disturbance. In the worst case, the average additional QBER only increases about 0.17% due to the disturbance, which is relatively small to normal QBER values. We also find the way to degrade the electromagnetic disturbance on the QKD system.

关键词： Faraday mirror electromagnetic disturbance quantum key distribution quantum bit error rate smart grid

Multiplexing Read-Out of Charge Qubits by a Superconducting Resonator

在线全文

学校读者我要写书评

暂无评论

chinese physics Letters 2016年第4期33卷 117-120页

作者：韩天一邓光伟魏达郭国平 Key Laboratory of quantum information Chinese Academy of SciencesUniversity of Science and Technology of China synergetic innovation Center of quantum information and quantum physics University of Science and Technology of China

Wavelength division multiplexing （WDM） is widely used in modern optics and electronics. For future quantum computers, the integration of readout is also vitally important. Here we incorporate an idea of WDM to demon- strate multiplexing readout of charge qubits by using a single integrated on-chip superconducting microwave resonator. Two distant qubits formed by two graphene double quantum dots （DQDs） are simultaneously readout by an interconnected superconducting resonator. This readout device is found to have 2 MHz bandwidth and 1.1 x 10-4 e/x/-H-z charge sensitivity. Different frequency gate-modulations, which are used selectively to change the impedance of the qubits, are applied to different DQDs, which results in separated sidebands in the spectrum. These sidebands enable a multiplexing readout for the multi-qubits circuit. This architecture can largely reduce the amount of detectors and can improve the prospect for scaling-up of semiconductor qubits.

关键词： of in on is by Multiplexing Read-Out of Charge Qubits by a Superconducting Resonator

All-optical modulation of quantum states by nonlinear metasurface

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第3期11卷 136-141页

作者： Di Zhang Yang Chen Shengchao Gong Wei Wu Wei Cai Mengxin Ren Xifeng Ren Shuang Zhang Guangcan Guo Jingjun Xu The Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationSchool of Physics and TEDA Applied Physics InstituteNankai UniversityTianjinChina Key Laboratory of quantum information CASUniversity of Science and Technology of ChinaHefeiChina synergetic innovation Center of quantum information&quantum physics University of Science and Technology of ChinaHefeiChina Collaborative innovation Center of Extreme Optics Shanxi UniversityTaiyuanChina Department of physics The University of Hong KongHong KongChina

Metasurfaces have proven themselves an exotic ability to harness light at nano-scale,being important not only for classical but also for quantum *** manipulation of the quantum states is at the heart of quantum information processing;however,such function has been rarely realized with metasurfaces so ***,we report an all-optical dynamic modulation of the photonic quantum states using the nonlinear *** metasurface consists of a metallic nanostructure combined with a photoisomerizable azo *** tuning the plasmonic resonance through optically switching the azo molecules between their binary isomeric states,we have realized dynamic control of transmission efficiencies of orthogonally polarized photons and also the phase delay between them,thereby an entangled state was efficiently *** an illustration,a quantum state distillation has been demonstrated to recover a Bell state from a non-maximally entangled one to that with fidelities higher than 98%.Our work would enrich the functions of the metasurface in the quantum world,from static to dynamic modulation,making the quantum metasurface going practical.

关键词： surface quantum nonlinear

Visible-light deposition of CrO_(x) cocatalyst on TiO_(2):Cr valence regulation for superior photocatalytic CO_(2)reduction to CH_(4)

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第1期31卷 103-112,I0004页

作者： Jingjing Dong Yuan Kong Heng Cao Zhiyu Wang Zhirong Zhang Lidong Zhang Song Sun Chen Gao Xiaodi Zhu Jun Bao National Synchrotron Radiation Laboratory Collaborative Innovation Center of Chemistry for Energy MaterialsUniversity of Science and Technology of ChinaHefei 230029AnhuiChina Hefei National Laboratory for Physical Science at the Microscale and Department of Chemical physics Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026AnhuiChina School of Chemistry and Chemical Engineering Anhui UniversityHefei 230601AnhuiChina School of Physical Science University of Chinese Academy of SciencesBeijing 100049China

Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on ***,it is prerequisite that the photon energy should be sufficient to excite the host ***,we report a lower-energy irradiation powered deposition strategy for implanting CrO_(x) cocatalyst on TiO_(2).Excitingly,CrO_(x)-400 implanted under visible-light irradiation significantly promotes the CH4 evolution rate on TiO_(2)to 8.4μmolg·^(-1)h^(-1) with selectivity of98%from photocatalytic CO_(2)reduction,which is 15 times of that on CrO_(x)-200 implanted under UV-visible-light ***,CrO_(x)-400 is identified to be composed of higher valence Cr species compared to CrO_(x)-*** valence states regulation of Cr species is indicated to provide more active sites for CO_(2) adsorption/activation and to modulate the reaction mechanism from single Cr site to Cr-Cr dual sites,thus endowing the superior CH_(4)*** work demonstrates an alternative strategy for constructing efficient metal oxides cocatalysts on wide bandgap semiconductor.

关键词： Valence states regulation CrO_(x)cocatalyst Lower-energy irradiation Photocatalytic CO_(2)reduction High CH_(4)selectivity

A Bright Single-Photon Source from Nitrogen-Vacancy Centers in Diamond Nanowires

在线全文

学校读者我要写书评

暂无评论

chinese physics Letters 2017年第9期34卷 70-73页

作者：李燊李翠红赵博文董杨李聪丛陈向东葛亚松孙方稳 Key Lab of quantum information Chinese Academy of SciencesUniversity of Science and Technology of China synergetic innovation Center of quantum information and quantum physics University of Science and Technology of China Institute of Geology and Geophysics Chinese Academy of Sciences University of chinese academy of sciences

Single-photon flux is one of the crucial properties of nitrogen vacancy （NV） centers in diamond for its application in quantum information techniques. Here we fabricate diamond conical nanowires to enhance the single-photon count rate. Through the interaction between tightly confined optical mode in nanowires and NV centers, the single-photon lifetime is much shortened and the collection efficiency is enhanced. As a result, the detected single-photon rate can be at 564 kcps, and the total detection coefficient can be 0.8%, which is much higher than that in bulk diamond. Such a nanowire single-photon device with high photon flux can be applied to improve the fidelity of quantum computation and the precision of quantum sensors.

关键词： A Bright Single-Photon Source from Nitrogen-Vacancy Centers in Diamond Nanowires

Spectrally multiplexed and bright entangled photon pairs in a lithium niobate microresonator

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2022年第9期65卷 3-9页

作者： Bo-Yu Xu Li-Kun Chen Jin-Tian Lin Lan-Tian Feng Rui Niu Zhi-Yuan Zhou Ren-Hong Gao Chun-Hua Dong Guang-Can Guo Qi-Huang Gong Ya Cheng Yun-Feng Xiao Xi-Feng Ren CAS Key Laboratory of quantum information University of Science and Technology of ChinaHefei 230026China State Key Laboratory for Mesoscopic physics and Frontiers Science Center for Nano-optoelectronics School of PhysicsPeking UniversityBeijing 100871China State Key Laboratory of High Field Laser physics and CAS Center for excellence in Ultra-intense Laser Science Shanghai Institute of Optics and Fine Mechanics(SIOM)Chinese Academy of Sciences(CAS)Shanghai 201800China CAS synergetic innovation Center of quantum information&quantum physics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China Collaborative innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

On-chip bright quantum sources with multiplexing ability are extremely high in demand for integrated quantum networks with unprecedented scalability and ***,we demonstrate a bright and broadband biphoton quantum source with spectral multiplexing generated in a lithium niobate microresonator *** introducing the conventional domain poling,the on-chip microdisk produces photon pairs covering a broad bandwidth promised by natural phase matching in spontaneous parametric down ***,the multiplexed photon pairs are characterized by 30 nm bandwidth limited by the filtering system,providing over 40 multiplexing channels with a 0.8 nm channel ***,the generation rate reaches 5.13 MHz/μW with a coincidence-to-accidental ratio up to 804,and the quantum source manifests a high purity with a heralded single photon correlation g^((2))_(H)(0)=0.0098±***,the energy-time entanglement is demonstrated with an excellent interference visibility of 96.5%±2%.Such a quantum source at the telecommunication band paves the way for high-dimensional entanglement and future integrated quantum information systems.

关键词： quantum entangled source spectral multiplexing lithium niobate on insulator microresonator

Adjustable unbalanced quantum random-number generator

在线全文

学校读者我要写书评

暂无评论

chinese Optics Letters 2015年第2期13卷 62-66页

作者：许曼莉黄靖正梁文烨张春梅王双银振强陈巍韩正甫 Key Laboratory of quantum information Chinese Academy of Sciences (CAS) University of Science and Technology of China synergetic innovation Center of quantum information and quantum physics University of Science and Technology of China

We report an adjustable unbalanced quantum random-number generator based on the polarization of photons,which can produce nondeterministic true random unbalanced numbers. The underlying physical process is inherently quantum mechanical. To prove the quality of the output sequence of the proposed generator, we test the obtained bias-free sequence through the 3-standard-deviation criteria and the National Institutes of Standards and Technology test suite. Another type of nondeterministic unbalanced random-number generator is also studied in this work, to evaluate the quality of the output biased random numbers.

关键词： Number theory quantum theory

Superconducting quantum computing: a review

在线全文

学校读者我要写书评

暂无评论

Science China(information sciences) 2020年第8期63卷 59-90页

作者： He-Liang HUANG Dachao WU Daojin FAN Xiaobo ZHU Hefei National Laboratory for Physical sciences at Microscale and Department of Modern physics University of Science and Technology of China Shanghai Branch CAS Centre for Excellence and Synergetic Innovation Centre in Quantum Information and Quantum PhysicsUniversity of Science and Technology of China

Over the last two decades, tremendous advances have been made for constructing large-scale quantum computers. In particular, quantum computing platforms based on superconducting qubits have become the leading candidate for scalable quantum processor architecture, and the milestone of demonstrating quantum supremacy has been first achieved using 53 superconducting qubits in 2019. In this study, we provide a brief review on the experimental efforts towards the large-scale superconducting quantum computer,including qubit design, quantum control, readout techniques, and the implementations of error correction and quantum algorithms. Besides the state of the art, we finally discuss future perspectives, and which we hope will motivate further research.

关键词： quantum computing superconducting quantum computing quantum bit quantum algorithm qubit design qubit control qubit readout

Improving Accuracy of Estimating Two-Qubit States with Hedged Maximum Likelihood

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese physics Letters 2017年第3期34卷 1-5页

作者：殷琪项国勇李传锋郭光灿 Key Laboratory of quantum information University of Science and Technology of ChinaChinese Academy of SciencesHefei 230026 synergetic innovation Center of quantum information and quantum physics University of Science and Technology of ChinaChinese Academy of SciencesHefei 230026

As a widely used reconstruction algorithm in quantum state tomography, maximum likelihood estimation tends to assign a rank-deficient matrix, which decreases estimation accuracy for certain quantum states. Fortunately, hedged maximum likelihood estimation （HMLE） [Phys. Rev. Lett. 105 （2010）200504] was proposed to avoid this problem. Here we study more details about this proposal in the two-qubit case and further improve its performance. We ameliorate the HMLE method by updating the hedging function based on the purity of the estimated state. Both performances of HMLE and ameliorated HMLE are demonstrated by numerical simulation and experimental implementation on the Werner states of polarization-entangled photons.

关键词： MLE Improving Accuracy of Estimating Two-Qubit States with Hedged Maximum Likelihood