The spin-wave (SW) N-particle path-entangled |N,0|0,N (NOON) state is an N-particle Fock state with two atomic spin-wave modes maximally entangled. Attributed to the property that the phase is sensitive to collective atomic motion, the SW NOON state can be utilized as an atomic interferometer and has promising application in quantum enhanced measurement. In this paper we propose an efficient protocol to deterministically produce the atomic SW NOON state by employing the Rydberg blockade. Possible errors in practical manipulations are analyzed. A feasible experimental scheme is suggested. Our scheme is far more efficient than the recent experimentally demonstrated one, which only creates a heralded second-order SW NOON state.

Ran Wei;博 赵;友金 邓;宇翱 陈;建伟 潘

Physical Review A - Atomic, Molecular, and Optical Physics

2011-6-20

Silicon single-photon avalanche diodes (SPADs) are core devices for single-photon detection in the visible and the near-infrared wavelength range and are widely used in many fields such as astronomy, biology, lidar, quantum optics, and quantum information. Due to limitations in their structural design and fabrication, however, the key parameters of detection efficiency and timing jitter cannot be optimized simultaneously. Here, we propose a nanostructured silicon SPAD that achieves high detection efficiency with excellent timing jitter over a broad spectral range. Our optical and electrical simulations show significant performance enhancement compared to conventional silicon SPAD devices. This nanostructured device can be easily fabricated and is thus well suited for practical applications.

Jian Ma;Ming Zhou;Zongfu Yu;Xiao Jiang;Yijie Huo;Kai Zang;Jun Zhang;James S. Harris;Ge Jin;Qiang Zhang;建伟 潘

Optica

2015-11-18

The diamond films were successfully fabricated on low-alloy steel substrate with Cr⁺/Cu^- Diamond interlayer deposited by magnetron sputtering for Cr/Cu and composite electroplating for Cu-dia-mond. The interfacial characteristics were investigated by indentation test and the surface morphology, phase structure and residual stress were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. The results show that the Cr layer on low-alloy substrate prevents Fe from diffusing to Cu/diamond interface effectively by converting into (Cr, Fe)₃C₂ and (Cr, Fe)₇C₃ in CVD diamond growth. Low residual stress detected in diamond film can be attributed to the chromium-iron carbide and copper layer for relieve of phase transformation and thermal stress during CVD cooling process. Concentric cracks with no delaminate area on the periphery of the indentation in 441N load shows good adhesion between diamond and low-alloy steel substrate.

Yun Yu;Wanqi Qiu;建伟 潘;Kesong Zhou

Cailiao Yanjiu Xuebao/Chinese Journal of Materials Research

2013-4

We report the preparation and storage of frequency-uncorrelated cavity-enhanced SPDC entangled photons. The frequency correlation is eliminated with a suitable pulsed pump. The storage of a single photon entangled with another flying photon is demonstrated.

Xian Min Jin;Jian Yang;Han Zhang;Han Ning Dai;Sheng Jun Yang;Tian Ming Zhao;Jun Rui;Yu He;Xiao Jiang;Fan Yang;Ge Sheng Pan;Zhen Sheng Yuan;友金 邓;增兵 陈;Xiao Hui Bao;博 赵;Shuai Chen;建伟 潘

2011

Quantum key distribution (QKD) ensures information-theoretic security for the distribution of random bits between two remote parties. To extend QKD applications to fiber-to-the-home optical communications, such as gigabit-capable passive optical networks (GPONs), an effective method is the use of wavelength-division multiplexing. However, the Raman scattering noise from intensive classical traffic and the huge loss introduced by the beam splitter in a GPON severely limits the performance of QKD. Here, we demonstrate the integration of QKD and a commercial GPON system with fiber lengths up to 14 km, in which the maximum splitting ratio of the beam splitter reaches 1:64. By placing the QKD transmitter on the optical line terminal side, we reduce the Raman noise collected at the QKD receiver. Using a bypass structure, the loss of the beam splitter is circumvented effectively. Our results pave the way to extending the applications of QKD to last-mile communications.

Wei Sun;Liu Jun Wang;Xiang Xiang Sun;Yingqiu Mao;Hua Lei Yin;Bi Xiao Wang;Teng Yun Chen;建伟 潘

Journal of Applied Physics

2018-1-28

This paper used the finite element method to analyze the cerebrovascular bifurcation. By comparison, we constructed two intracranial artery bifurcation vessel models with different angles, and considered different model how to influence vascular blood flow based on the basic principles of hemodynamics. Through experiment, we mainly computed the value of blood velocity and wall pressure, and compared the difference of hemodynamic parameters in Model I and II tube. Finally, we found that the blood flow in tube associate with the angle of branch vessels. This will provide the theoretical basis to the hemodynamics of the real vessel.

Lingna He;建伟 潘

2010

The preparation and storage of photonic entanglement are central to the achievement of scalable linear optical quantum computation (LOQC). The most widely used photonic entanglement source (a spontaneous parametric downconversion (SPDC) source) is not directly suitable for storage, because its working frequency bandwidth is significantly larger than any available quantum memory. To remedy this problem, cavity-enhanced narrow-band SPDC sources have been developed. However, the storage of cavity-enhanced narrow-band entangled photons has not yet been achieved. Also, the spectral correlations between the entangled photons can make them practically useless for scalable LOQC. Here, we report the preparation and storage of frequency-uncorrelated narrowband (5 MHz) entangled photons from a cavity-enhanced SPDC source. The frequency correlation between the entangled photons is eliminated by changing the continuous UV pumping beam to short pulses. The storage of the polarization state of a single photon, and of a photon entangled with another flying in the fibre, is demonstrated. Our work demonstrates a quantum interface between narrow-band entangled photons from cavity SPDC and atomic quantum memory, and thus provides an important tool towards the achievement of all-optical quantum information processing.

Han Zhang;Xian Min Jin;Jian Yang;Han Ning Dai;Sheng Jun Yang;Tian Ming Zhao;Jun Rui;Yu He;Xiao Jiang;Fan Yang;Ge Sheng Pan;Zhen Sheng Yuan;友金 邓;增兵 陈;Xiao Hui Bao;Shuai Chen;博 赵;建伟 潘

Nature Photonics

2011-10

D. Bouwmeester;建伟 潘;M. Daniell;H. Weinfurter;M. Zukowski;A. Zeilinger

Nature

1998-8-27

Silicon single-photon detectors (SPDs) are the key devices for detecting single photons in the visible wavelength range. Here we present high detection efficiency silicon SPDs dedicated to the generation of multiphoton entanglement based on the technique of high-frequency sine wave gating. The silicon single-photon avalanche diode components are acquired by disassembling 6 commercial single-photon counting modules (SPCMs). Using the new quenching electronics, the average detection efficiency of SPDs is increased from 68.6% to 73.1% at a wavelength of 785 nm. These sine wave gating SPDs are then applied in a four-photon entanglement experiment, and the four-fold coincidence count rate is increased by 30% without degrading its visibility compared with the original SPCMs.

Nan Zhou;Wen Hao Jiang;Luo Kan Chen;Yu Qiang Fang;Zheng Da Li;Hao Liang;宇翱 陈;Jun Zhang;建伟 潘

Review of Scientific Instruments

2017-8-1

Direct current field enhanced pack boriding (DCFEPB) was performed at 800℃ by applying DCF on 45 steel samples and boriding agent. X-ray diffraction, optical microscope and micro-hardness testing were employed to characterize phases, micro-structure and property of the boronized case. The results show that the serrated boronized layer is observed for both DCFEPB and conventional pack boriding. However, the phases, micro-structure, thickness and micro-hardness distribution for the DCFEPB cases show a close relation with the location of the samples in the chamber. The boriding case of the sample surface facing anode is generally composed of FeB and Fe₂B, which is thicker and harder. The boriding case of the sample surface facing cathode mainly consists of Fe₂B, and the amount of FeB phase in the boriding case increases first and then decreases to zero with prolonging boriding time. A diffusion zone emerges underneath the DCFEPB case when the boriding time is equal to and longer than 2 h. The curves of boriding case thickness versus boriding time show a parabolic characteristic. It is argued that DCF influences the reactions of boriding agent, diffusion of boron-containing active radicals in the atmosphere and diffusion of boron in the samples.

Xiao Juan Wang;Fei Xie;Jian Cheng;建伟 潘

Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment

2015-2-25