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Research on the correlation between the dual diffusion behavior of zinc in InGaAs/InP single-photon avalanche photodiodes and device performance
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作者 LIU Mao-Fan YU Chun-Lei +7 位作者 MA Ying-Jie YU Yi-Zhen YANG Bo TIAN Yu BAO Peng-Fei CAO Jia-Sheng LIU Yi LI Xue 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2024年第5期595-602,共8页
The development of InGaAs/InP single-photon avalanche photodiodes(SPADs)necessitates the utiliza-tion of a two-element diffusion technique to achieve accurate manipulation of the multiplication width and the dis-tribu... The development of InGaAs/InP single-photon avalanche photodiodes(SPADs)necessitates the utiliza-tion of a two-element diffusion technique to achieve accurate manipulation of the multiplication width and the dis-tribution of its electric field.Regarding the issue of accurately predicting the depth of diffusion in InGaAs/InP SPAD,simulation analysis and device development were carried out,focusing on the dual diffusion behavior of zinc atoms.A formula of X_(j)=k√t-t_(0)+c to quantitatively predict the diffusion depth is obtained by fitting the simulated twice-diffusion depths based on a two-dimensional(2D)model.The 2D impurity morphologies and the one-dimensional impurity profiles for the dual-diffused region are characterized by using scanning electron micros-copy and secondary ion mass spectrometry as a function of the diffusion depth,respectively.InGaAs/InP SPAD devices with different dual-diffusion conditions are also fabricated,which show breakdown behaviors well consis-tent with the simulated results under the same junction geometries.The dark count rate(DCR)of the device de-creased as the multiplication width increased,as indicated by the results.DCRs of 2×10^(6),1×10^(5),4×10^(4),and 2×10^(4) were achieved at temperatures of 300 K,273 K,263 K,and 253 K,respectively,with a bias voltage of 3 V,when the multiplication width was 1.5µm.These results demonstrate an effective prediction route for accu-rately controlling the dual-diffused zinc junction geometry in InP-based planar device processing. 展开更多
关键词 InGaAs/InP single-photon avalanche photodiode diffusion depth Znic diffusion dark count rate
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Improved decoy-state quantum key distribution with uncharacterized heralded single-photon sources
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作者 徐乐辰 张春辉 +1 位作者 周星宇 王琴 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期204-208,共5页
Encoding system plays a significant role in quantum key distribution(QKD).However,the security and performance of QKD systems can be compromised by encoding misalignment due to the inevitable defects in realistic devi... Encoding system plays a significant role in quantum key distribution(QKD).However,the security and performance of QKD systems can be compromised by encoding misalignment due to the inevitable defects in realistic devices.To alleviate the influence of misalignments,a method exploiting statistics from mismatched basis is proposed to enable uncharacterized sources to generate secure keys in QKD.In this work,we propose a scheme on four-intensity decoy-state quantum key distribution with uncharacterized heralded single-photon sources.It only requires the source states are prepared in a two-dimensional Hilbert space,and can thus reduce the complexity of practical realizations.Moreover,we carry out corresponding numerical simulations and demonstrate that our present four-intensity decoy-state scheme can achieve a much higher key rate compared than a three-intensity decoy-state method,and meantime it can obtain a longer transmission distance compared than the one using weak coherent sources. 展开更多
关键词 quantum key distribution heralded single-photon source decoy-state method
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Dynamic modulated single-photon routing
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作者 李浩珍 曾然 +5 位作者 胡淼 许蒙蒙 周雪芳 夏秀文 许静平 羊亚平 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期332-340,共9页
The dynamic control of single-photon scattering in a pair of one-dimensional waveguides mediated by a time-modulated atom-cavity system is investigated.Two cases,where the waveguides are coupled symmetrically or asymm... The dynamic control of single-photon scattering in a pair of one-dimensional waveguides mediated by a time-modulated atom-cavity system is investigated.Two cases,where the waveguides are coupled symmetrically or asymmetrically to the atom-cavity system,are discussed in detail.The results show that such time-modulated atom-cavity configuration can behave as a dynamical tunable directional single-photon router.The photons with different frequencies can dynamically be routed from the incident waveguide into any ports of the other with a 100%probability via adjusting the modulated amplitude or phases of the time-modulated atom-cavity coupling strengths,associate with the help of the asymmetrical waveguide-cavity couplings.Furthermore,the influence of dissipation on the routing capability is investigated.It is shown that the present single-photon router is robust against the dissipative process of the system,especially the atomic dissipation.These results are expected to be applicable in quantum information processing and design quantum devices with dynamical modulation. 展开更多
关键词 single-photon router dynamical modulation waveguide-QED
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Model and data of optically controlled tunable capacitor in silicon single-photon avalanche diode
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作者 曾美玲 汪洋 +2 位作者 金湘亮 彭艳 罗均 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期564-569,共6页
This paper reports the photocapacitance effect of silicon-based single-photon avalanche diodes(SPADs),and the frequency scattering phenomenon of capacitance.The test results of the small-signal capacitance-voltage met... This paper reports the photocapacitance effect of silicon-based single-photon avalanche diodes(SPADs),and the frequency scattering phenomenon of capacitance.The test results of the small-signal capacitance-voltage method show that light can cause the capacitance of a SPAD device to increase under low-frequency conditions,and the photocapacitance exhibits frequency-dependent characteristics.Since the devices are fabricated based on the standard bipolar-CMOS-DMOS process,this study attributes the above results to the interfacial traps formed by Si-SiO_(2),and the illumination can effectively reduce the interfacial trap lifetime,leading to changes in the junction capacitance inside the SPAD.Accordingly,an equivalent circuit model considering the photocapacitance effect is also proposed in this paper.Accurate analysis of the capacitance characteristics of SPAD has important scientific significance and application value for studying the energy level distribution of device interface defect states and improving the interface quality. 展开更多
关键词 photocapacitance effect single-photon avalanche diode interfacial traps
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A New Method to Investigate InGaAsP Single-Photon Avalanche Diodes Using a Digital Sampling Oscilloscope
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作者 刘伟 杨富华 吴孟 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第10期1711-1716,共6页
A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode (Geiger-mode) sin... A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode (Geiger-mode) single-photon detection are intuitionally demonstrated for the first time. The performance of the detector as a gated-mode single-photon counter at wavelengths of 1310 and 1550nm is investigated. At the operation temperature of 203K,a quantum efficiency of 52% with a dark count probability per gate of 2.4 × 10 ^-3 ,and a gate pulse repetition rate of 50kHz are obtained at 1550nm. The corresponding parameters are 43%, 8.5 × 10^-3 , and 200kHz at 238K. 展开更多
关键词 InGaAsP single-photon avalanche diode 50GHz digital sampling oscilloscope gated-mode
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Hepatic clearance measured with ^(99m)Tc-GSA single-photon emission computed tomography to estimate liver fibrosis 被引量:12
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作者 Masahiko Taniguchi Atsutaka Okizaki +6 位作者 Kenji Watanabe Koji Imai Koichiro Uchida Takahiro Einama Noriyuki Shuke Naoyuki Miyokawa Hiroyuki Furukawa 《World Journal of Gastroenterology》 SCIE CAS 2014年第44期16714-16720,共7页
AIM: To evaluate the clinical utility of hepatic clearance(HC) measured with technetium-99m-diethylenetriaminepenta-acetic acid-galactosyl human serum albumin(99mTc-GSA) single-photon emission computed tomography(SPEC... AIM: To evaluate the clinical utility of hepatic clearance(HC) measured with technetium-99m-diethylenetriaminepenta-acetic acid-galactosyl human serum albumin(99mTc-GSA) single-photon emission computed tomography(SPECT) to estimate the degree of liver fibrosis.METHODS:Seventy-eight consecutive patients who underwent initial hepatectomy due to hepatocellular carcinoma were enrolled in this study.Indocyanine green clearance(ICG R15),quantitative indices estimated by 99mTc-GSA[the receptor index(LHL15 and HH15)and HC via SPECT analysis],and conventional liver function tests were performed before hepatectomy.Correlations among the quantitative indices for liver functional reserve,conventional liver function tests,andthe degree of liver fibrosis were evaluated.RESULTS:The degree of liver fibrosis was correlated with ICG R15,HH15,LHL15,and HC.HC showed the best correlation with conventional liver function tests.According to multivariate analysis,HC and LHL15 were significant independent predictors of severe fibrosis.HC was the most valuable index for predicting severe fibrosis.CONCLUSION:HC measured with 99mTc-GSA SPECT is a reliable index for assessing liver fibrosis before hepatectomy. 展开更多
关键词 FIBROSIS Technetium-99m-diethylenetri-aminepenta-acetic acid-galactosyl human serum albu-min single-photon emission computed tomography Hepatic clearance Liver resection
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Cerebral functional imaging of Waiguan (SJ 5) acupoint specificity using single-photon emission computed tomography 被引量:2
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作者 Yong Huang Yangjia Lu +5 位作者 Ganlong Li Xinsheng Lai Hong Zhang Chunzhi Tang JunjunYang Gustav Wik 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第6期428-434,共7页
The action of needling in acupoint therapy has to first be regulated and integrated by the brain, and then it affects the target organ and manifests its therapeutic effects, which is dependent on the specificity of th... The action of needling in acupoint therapy has to first be regulated and integrated by the brain, and then it affects the target organ and manifests its therapeutic effects, which is dependent on the specificity of the acupoints. The authors put forward the hypothesis of the "acupoint-related brain". Single-photon emission computed tomography was used to explore the activation of brain regions following true needling in true acupoint Waiguan (SJ 5), sham needling in true acupoint Waiguan, true needling in a sham point, and sham needling in a sham point. The relative specificity of Waiguan in normal persons was analyzed by observing changes in regional cerebral blood flow. Compared with the sham needling in true acupoint group and sham needling in the sham point group, acupuncture at Waiguan can activate brain regions controlling movement. Compared with true needling in the sham point group, acupuncture at Waiguan can also activate brain regions controlling movement. The results suggest that the specificity of needling at an acupoint is related to certain activated cerebral functional regions, which are associated with the clinical application of the acupoint. 展开更多
关键词 acupoint specificity Waiguan (SJ 5) NEEDLING sham needling sham point single-photon emission computed tomography
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Cavity optomechanics: Manipulating photons and phonons towards the single-photon strong coupling 被引量:2
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作者 刘玉龙 王冲 +1 位作者 张靖 刘玉玺 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期166-183,共18页
Cavity optomechanical systems provide powerful platforms to manipulate photons and phonons, open potential ap- plications for modern optical communications and precise measurements. With the refrigeration and ground-s... Cavity optomechanical systems provide powerful platforms to manipulate photons and phonons, open potential ap- plications for modern optical communications and precise measurements. With the refrigeration and ground-state cooling technologies, studies of cavity optomechanics are making significant progress towards the quantum regime including non- classical state preparation, quantum state tomography, quantum information processing, and future quantum internet. With further research, it is found that abundant physical phenomena and important applications in both classical and quan- tum regimes appeal as they have a strong optomechanical nonlinearity, which essentially depends on the single-photon optomechanical coupling strength. Thus, engineering the optomechanical interactions and improving the single-photon optomechanical coupling strength become very important subjects. In this article, we first review several mechanisms, theoretically proposed for enhancing optomechanical coupling. Then, we review the experimental progresses on enhancing optomechanical coupling by optimizing its structure and fabrication process. Finally, we review how to use novel structures and materials to enhance the optomechanical coupling strength. The manipulations of the photons and phonons at the level of strong optomechanical coupling are also summarized. 展开更多
关键词 optomechanical systems single-photon strong coupling controllable photons and phonons trans-port
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Noiseless linear amplification for the single-photon entanglement of arbitrary polarization–time-bin qudit 被引量:1
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作者 Ling-Quan Chen Yu-Bo Sheng Lan Zhou 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期210-217,共8页
Single-photon entanglement(SPE) is an important source in quantum communication. In this paper, we put forward a single-photon-assisted noiseless linear amplification protocol to protect the SPE of an arbitrary polari... Single-photon entanglement(SPE) is an important source in quantum communication. In this paper, we put forward a single-photon-assisted noiseless linear amplification protocol to protect the SPE of an arbitrary polarization–time-bin qudit from the photon transmission loss caused by the practical channel noise. After the amplification, the fidelity of the SPE can be effectively increased. Meanwhile, the encoded polarization–time-bin features of the qudit can be well preserved. The protocol can be realized under the current experimental conditions. Moreover, the amplification protocol can be extended to resist complete photon loss and partial photon loss during the photon transmission. After the amplification, we can not only increase the fidelity of the target state, but also solve the decoherence problem simultaneously. Based on the above features, our amplification protocol may be useful in future quantum communication. 展开更多
关键词 single-photon ENTANGLEMENT noiseless linear AMPLIFICATION polarization–time-bin QUDIT complete and partial photon loss
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Micropillar Cavity Design for 1.55-μm Quantum-Dot Single-Photon Sources 被引量:1
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作者 Hai-Zhi Song Wei Zhang +1 位作者 Li-Bo Yu Zhiming M.Wang 《Journal of Electronic Science and Technology》 CAS CSCD 2019年第3期221-230,共10页
The 1.55-μm quantum-dot (QD) micropillar cavities are strongly required as single photon sources (SPSs) for silica-fiber-based quantum information processing. Theoretical analysis shows that the adiabatic distributed... The 1.55-μm quantum-dot (QD) micropillar cavities are strongly required as single photon sources (SPSs) for silica-fiber-based quantum information processing. Theoretical analysis shows that the adiabatic distributed Bragg reflector (DBR) structure may greatly improve the quality of a micropillar cavity. An InGaAsP/InP micropillar cavity is originally difficult, but it becomes more likely usable with inserted tapered (thickness decreased towards the center) distributed DBRs. Simulation turns out that, incorporating adiabatically tapered DBRs, a Si/SiO2- InP hybrid micropillar cavity, which enables weakly coupling InAs/InP quantum dots (QDs), can even well satisfy strong coupling at a smaller diameter. Certainly, not only the tapered structure, other adiabatic designs, e.g., both DBR layers getting thicker and one thicker one thinner, also improve the quality, reduce the diameter, and degrade the fabrication difficulty of Si/SiO2-InP hybrid micropillar cavities. Furthermore, the problem of the thin epitaxial semiconductor layer can also be greatly resolved by inserting adiabatic InGaAsP/InP DBRs. With tapered DBRs, the InGaAsP/InP-air-aperture micro-pillar cavity serves as an efficient, coherent, and monolithically producible 1.55-μm single-photon source (SPS). The adiabatic design is thus an effective way to obtain prospective candidates for 1.55-μm QD SPSs. 展开更多
关键词 CAVITY distributed BRAGG reflectors(DBRs) micropillar quantum dot(QD) single-photon source(SPS)
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Round-Robin Differential Phase Shift with Heralded Single-Photon Source 被引量:1
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作者 Ying-Ying Zhang Wan-Su Bao +3 位作者 Chun Zhou Hong-Wei Li Yang Wang Mu-Sheng Jiang 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第4期1-4,共4页
Round-robin differential phase shift (RRDPS) is a novel quantum key distribution protocol which can bound information leakage without monitoring signal disturbance. In this work, to decrease the effect of the vacuum... Round-robin differential phase shift (RRDPS) is a novel quantum key distribution protocol which can bound information leakage without monitoring signal disturbance. In this work, to decrease the effect of the vacuum component in a weak coherent pulses source, we employ a practical decoy-state scheme with heralded singlephoton source for the RRDPS protocol and analyze the performance of this method. In this scheme, only two decoy states are needed and the yields of single-photon state and multi-photon states, as well as the bit error rates of each photon states, can be estimated. The final key rate of this scheme is bounded and simulated over transmission distance. The results show that the two-decoy-state method with heralded single-photon source performs better than the two-decoy-state method with weak coherent pulses. 展开更多
关键词 Round-Robin Differential Phase Shift with Heralded single-photon Source WCP
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A High-Efficiency Broadband Superconducting Nanowire Single-Photon Detector with a Composite Optical Structure 被引量:1
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作者 顾敏 康琳 +6 位作者 张蜡宝 赵清源 郏涛 万超 徐睿莹 杨小忠 吴培亨 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第3期145-148,共4页
Superconducting nanowire single-photon detectors (SNSPDs) with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and t... Superconducting nanowire single-photon detectors (SNSPDs) with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and the response bandwidth. Numerical simulation by the finite-difference time-domain method shows that the photon absorption capacity of SNSPDs with a composite optical structure can be enhanced significantly by adjusting the parameters of the phase-grating and optical cavity structures at multiple frequency bands. The absorption capacity of the superconducting nanowires reaches 70%, 72%, 60.73%, 61.7%, 41.2%, and 46.5% at wavelengths of 684, 850, 732, 924, 1256, and 1426nm, respectively. The use of a composite optical structure reduces the total filling factor of superconducting nanowires to only 0.25, decreases the kinetic inductance of SNSPDs, and improves the count rates. 展开更多
关键词 LENGTH A High-Efficiency Broadband Superconducting Nanowire single-photon Detector with a Composite Optical Structure
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Wavelength dependence of intrinsic detection efficiency of NbN superconducting nanowire single-photon detector
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作者 Yong Wang Hao Li +8 位作者 Li-Xing You Chao-Lin Lv He-Qing Wang Xing-Yu Zhang Wei-Jun Zhang Hui Zhou Lu Zhang Xiao-Yan Yang Zhen Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第7期534-537,共4页
Superconducting nanowire single-photon detectors(SNSPDs) have attracted considerable attention owing to their excellent detection performance;however, the underlying physics of the detection process is still unclear.I... Superconducting nanowire single-photon detectors(SNSPDs) have attracted considerable attention owing to their excellent detection performance;however, the underlying physics of the detection process is still unclear.In this study, we investigate the wavelength dependence of the intrinsic detection efficiency(IDE) for NbN SNSPDs.We fabricate various NbN SNSPDs with linewidths ranging from 30 nm to 140 nm.Then, for each detector, the IDE curves as a function of bias current for different incident photon wavelengths of 510–1700 nm are obtained.From the IDE curves, the relations between photon energy and bias current at a certain IDE are extracted.The results exhibit clear nonlinear energy–current relations for the NbN detectors, indicating that a detection model only considering quasiparticle diffusion is unsuitable for the meander-type NbN-based SNSPDs.Our work provides additional experimental data on SNSPD detection mechanism and may serve as an interesting reference for further investigation. 展开更多
关键词 NIOBIUM NITRIDE SUPERCONDUCTING NANOWIRE single-photon detectors detection mechanism
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Dark count in single-photon avalanche diodes:A novel statistical behavioral model
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作者 Wen-Juan Yu Yu Zhang +1 位作者 Ming-Zhu Xu Xin-Miao Lu 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第4期523-529,共7页
Dark count is one of the inherent noise types in single-photon diodes,which may restrict the performances of detectors based on these diodes.To formulate better designs for peripheral circuits of such diodes,an accura... Dark count is one of the inherent noise types in single-photon diodes,which may restrict the performances of detectors based on these diodes.To formulate better designs for peripheral circuits of such diodes,an accurate statistical behavioral model of dark current must be established.Research has shown that there are four main mechanisms that contribute to the dark count in single-photon avalanche diodes.However,in the existing dark count models only three models have been considered,thus leading to inaccuracies in these models.To resolve these shortcomings,the dark current caused by carrier diffusion in the neutral region is deduced by multiplying the carrier detection probability with the carrier particle current at the boundary of the depletion layer.Thus,a comprehensive dark current model is constructed by adding the dark current caused by carrier diffusion to the dark current caused by the other three mechanisms.To the best of our knowledge,this is the first dark count simulation model into which incorporated simultaneously are the thermal generation,trap-assisted tunneling,band-to-band tunneling mechanisms,and carrier diffusion in neutral regions to evaluate dark count behavior.The comparison between the measured data and the simulation results from the models shows that the proposed model is more accurate than other existing models,and the maximum of accuracy increases up to 31.48%when excess bias voltage equals 3.5 V and temperature is 50℃. 展开更多
关键词 single-photon AVALANCHE diode DARK COUNT STATISTICAL BEHAVIORAL modeling carrier diffusion
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Time-Bin Phase-Encoding Measurement-Device-Independent Quantum Key Distribution with Four Single-Photon Detectors
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作者 唐光召 孙仕海 +2 位作者 陈欢 李春燕 梁林梅 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第12期5-8,共4页
Measurement-device-independent quantum key distribution (MDI-QKD) eliminates all loopholes on detection. 3 loss in the final key for the Previous experiments of time-bin phase-encoding MDI-QKD allow a factor of inc... Measurement-device-independent quantum key distribution (MDI-QKD) eliminates all loopholes on detection. 3 loss in the final key for the Previous experiments of time-bin phase-encoding MDI-QKD allow a factor of incapability of identifying two successive detection events by a single photon detector. Here we propose a new scheme to realize the time-bin phase-encoding MDI-QKD. The polarization states are used to generate the time bins and the phase-encoding states. The factor of loss in the final key is eliminated by using four single photon detectors at the measurement site. We show the feasibility of our scheme with a proof-of-principle experimental demonstration. The phase reference frame is rotated extremely slowly with only passive stabilization measures. The quantum bit error rate can reach 0.8% in the Z-basis and 26.2% in the X-basis. 展开更多
关键词 QKD MDI of Time-Bin Phase-Encoding Measurement-Device-Independent Quantum Key Distribution with Four single-photon Detectors in QBER is with
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Passively stabilized single-photon interferometer
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作者 Hai-Long Liu Min-Jie Wang +4 位作者 Jia-Xin Bao Chao Liu Ya Li Shu-Jing Li Hai Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第11期231-235,共5页
A single-photon interferometer is a fundamental element in quantum information science.In most previously reported works,single-photon interferometers use an active feedback locking system to stabilize the relative ph... A single-photon interferometer is a fundamental element in quantum information science.In most previously reported works,single-photon interferometers use an active feedback locking system to stabilize the relative phase between two arms of the interferometer.Here,we use a pair of beam displacers to construct a passively stable single-photon interferometer.The relative phase stabilization between the two arms is achieved by stabilizing the temperature of the beam displacers.A purely polarized single-photon-level pulse is directed into the interferometer input port.By analyzing and measuring the polarization states of the single-photon pulse at the output port,the achieved polarization fidelity of the interferometer is about 99.1±0.1%.Our passively stabilized single-photon interferometer provides a key element for generating highfidelity entanglement between a photon and atomic memory. 展开更多
关键词 passively stable single-photon interferometer atom-photon entanglement polarization fidelity
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Single-photon modulation spectrum
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作者 刘岩 于波 +3 位作者 何博 张国峰 肖连团 贾锁堂 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第1期30-34,共5页
We present a robust method of single-photon modulation by directly modulating the single photons and observe its fre- quency spectrum. Compared with conventional photon counting technique, the single-photon modulation... We present a robust method of single-photon modulation by directly modulating the single photons and observe its fre- quency spectrum. Compared with conventional photon counting technique, the single-photon modulation spectrum shows that the method could not only realize high-frequency modulation but also obtain higher signal-to-noise ratio. Moreover, the theoretical calculations show good agreement with the experimental results. 展开更多
关键词 signal-to-noise ratio single-photon modulation SPECTRUM
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Brightening single-photon emitters by combining an ultrathin metallic antenna and a silicon quasi-BIC antenna
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作者 Shangtong Jia Zhi Li Jianjun Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第1期313-319,共7页
Bright single-photon emitters(SPEs)are fundamental components in many quantum applications.However,it is difficult to simultaneously get large Purcell enhancements and quantum yields in metallic nanostructures because... Bright single-photon emitters(SPEs)are fundamental components in many quantum applications.However,it is difficult to simultaneously get large Purcell enhancements and quantum yields in metallic nanostructures because of the huge losses in the metallic nanostructures.Herein,we propose to combine an ultrathin metallic bowtie antenna with a silicon antenna above a metallic substrate to simultaneously get large Purcell enhancements,quantum yields,and collection efficiencies.As a result,the brightness of SPEs in the hybrid nanostructure is greatly increased.Due to the deep subwavelength field confinement(mode size<10 nm)of surface plasmons in the ultrathin metallic film(thickness<4 nm),the Purcell enhancement of the metallic bowtie antenna improves by more than 25 times when the metal thickness decreases from 20 nm to 2 nm.In the hybrid nanostructures by combining an ultrathin metallic bowtie antenna with a silicon antenna,the Purcell enhancement(Fp≈2.6×10^(6))in the hybrid nanostructures is 63 times greater than those(≤4.1×10^(4))in the previous metallic and hybrid nanostructures.Because of the reduced ratio of electromagnetic fields in the ultrathin metallic bowtie antenna when the high-index silicon antenna is under the quasi-BIC state,a high quantum yield(QY≈0.70)is obtained.Moreover,the good radiation directivity of the quasi-BIC(bound state in the continuum)mode of the silicon antenna and the reflection of the metallic substrate result in a high collection efficiency(CE≈0.71).Consequently,the overall enhancement factor of brightness of a SPE in the hybrid nanostructure is EF∗≈Fp×QY×CE≈1.3×10^(6),which is 5.6×10^(2) times greater than those(EF∗≤2.2×103)in the previous metallic and hybrid nanostructures. 展开更多
关键词 single-photon emitters brightness hybrid nanostructures ultrathin metallic antenna quasi-bound state in the continuum(BIC)
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Controlling a sine wave gating single-photon detector by exploiting its filtering loophole
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作者 Lin-Xi Feng Mu-Sheng Jiang +3 位作者 Wan-Su Bao Hong-Wei Li Chun Zhou Yang Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第8期124-129,共6页
GHz single-photon detector (SPD) is a crucial part in the practical high speed quantum key distribution (QKD) system. However, any imperfections in a practical QKD system may be exploited by an eavesdropper (Eve... GHz single-photon detector (SPD) is a crucial part in the practical high speed quantum key distribution (QKD) system. However, any imperfections in a practical QKD system may be exploited by an eavesdropper (Eve) to collect information about the key without being discovered. The sine wave gating SPD (SG-SPD) based on InGaAs/InP avalanche photodiode, one kind of practical high speed SPD, may also contain loopholes. In this paper, we study the principle and characteristic of the SG-SPD and find out the filtering loophole of the SG-SPD for the first time. What is more, the proof-of-principle experiment shows that Eve could blind and control Bob's SG-SPD by exploiting this loophole. We believe that giving enough attention to this loophole can improve the practical security of the existing QKD system. GHz single-photon detector (SPD) is a crucial part in the practical high speed quantum key distribution (QKD) system. However, any imperfections in a practical QKD system may be exploited by an eavesdropper (Eve) to collect information about the key without being discovered. The sine wave gating SPD (SG-SPD) based on InGaAs/InP avalanche photodiode, one kind of practical high speed SPD, may also contain loopholes. In this paper, we study the principle and characteristic of the SG-SPD and find out the filtering loophole of the SG-SPD for the first time. What is more, the proof-of-principle experiment shows that Eve could blind and control Bob's SG-SPD by exploiting this loophole. We believe that giving enough attention to this loophole can improve the practical security of the existing QKD system. 展开更多
关键词 quantum key distribution sine wave gating single-photon detector quantum hacking practicalsecurity
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Single-photon scattering controlled by an imperfect cavity
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作者 Liwei Duan Qing-Hu Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第7期234-239,共6页
We study the single-photon transport in the coupled-resonator waveguide(CRW)controlled by an imperfect cavity.A Lorentzian spectrum is introduced to describe the dissipation.We find that the probability current conser... We study the single-photon transport in the coupled-resonator waveguide(CRW)controlled by an imperfect cavity.A Lorentzian spectrum is introduced to describe the dissipation.We find that the probability current conservation can be broken,although the imperfect cavity is a Hermitian system.The coupling strength between the imperfect cavity and the CRW has significant influences near the resonant frequency.With the increase of the coupling strength,the transmission coeffi-cient becomes smaller.The spectral width plays a dominant role under the off-resonant condition,where the transmission coefficient is greatly suppressed with the increase of the spectral width.We also observe an abrupt jump of the transmission and reflection coefficients when the hopping amplitude is large enough.All the distinctive behaviors are closely related to the complex effective potential induced by the imperfect cavity. 展开更多
关键词 single-photon scattering coupled-resonator waveguide imperfect cavity
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