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1.
H. F. Wang S. Zhang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(3):359-363
We propose a simple experimental scheme to prepare a type of
four-photon entangled state |χ〉 that has many interesting
entanglement properties and possible applications in quantum
information processing with a certain success probability. The
proposed setup involves only simple linear optical devices, a
single-photon polarization state, three pairs of two-photon
polarization entangled states, and the conventional photon detectors
that cannot distinguish a single photon from two or more photons,
which greatly simplify the experimental realization of the scheme. 相似文献
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近几十年来,超导单光子探测技术被越来越广泛的应用于量子保密通信与线性光量子计算等重要领域中.其中,基于超导共面波导谐振器的单光子技术以其结构简单,高探测效率及可分辨光子数目等特性吸引了人们越来越多的关注.随着科研工作者对样品制备工艺的不断改进,对选用超导薄膜材料的不断优化,以及对相关背景理论的深入研究,共面波导谐振器单光子探测技术在近几年中取得了巨大的突破.本文将从共面波导谐振器单光子探测器的工作原理,相关理论研究,样品参数设计等方面出发,结合本实验室近期测试得到的实验结果,对共面波导谐振器单光子探测技术的发展近况进行简要的综述. 相似文献
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In t.his contribution, we briefly recall the basic concepts of quantum optics and properties of semicon- ductor quantum clot. (QD) which a.re necessary to the nnderstanding of the physics of single-photon generation with single QDs. Firstly, we address the theory of quantmn emitter-cavity system, the fluorescence and optical properties of semiconductor QDs, and the photon statistics as well as opti- cal properties of the QDs. We then review the localizatioll of single semiconductor QDs in quantum confined optical microcavity systems to achieve their overall optical properties and perfornances in terms of strong coupling regime, elfieiency, directionality, and polarization control. Furthermore, we will discuss the recenl, progress on the fabrication of single photon sources, and various a.pproaehes for embedding single QDs into mieroca,vities or photonic crystal nanoeavities and show how to ex- tend the wavelength range. We focus in part;icular on new generations of electrically driven QD single photon source leading to high repetition rates, efficiencies at elevated temperature operation. Besides strong eoupling regime, and high collection new development;s of room temperature sin- gle photon emission in the strong coupling regime are reviewed. The generation of indistinguishable photons and remaining challenges for pract ical single-photon sources are also discussed. 相似文献
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量子信息技术近十多年来的快速发展对单光子探测器的性能提出了更高的要求,高性能单光子探测器也因此受到了更多的关注.与传统的单光子探测器相比,超导转变边沿(TES)单光子探测器在探测效率、能量分辨、光子数分辨和暗计数等方面具有突出优势.目前,超导TES单光子探测器已经被成功地应用在量子光学实验和量子密钥分配系统中,未来在量子信息技术等研究领域具有更广泛的应用.本文从超导TES单光子探测器的工作原理、制备流程、测试系统、主要性能指标以及研究现状和进展等方面对该探测器技术进行简要综述. 相似文献
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We analyze the coherent transport of a single photon, which propagates in a one-dimensional coupled-resonator waveguide and is scattered by a controllable two-level system located inside one of the resonators of this waveguide. Our approach, which uses discrete coordinates, unifies low and high energy effective theories for single-photon scattering. We show that the controllable two-level system can behave as a quantum switch for the coherent transport of a single photon. This study may inspire new electro-optical single-photon quantum devices. We also suggest an experimental setup based on superconducting transmission line resonators and qubits. 相似文献
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WeiJun Zhang LiXing You Hao Li Jia Huang ChaoLin Lv Lu Zhang XiaoYu Liu JunJie Wu Zhen Wang XiaoMing Xie 《中国科学:物理学 力学 天文学(英文版)》2017,60(12):120314
The rapid development of superconducting nanowire single-photon detectors over the past decade has led to numerous advances in quantum information technology. The record for the best system detection efficiency at an incident photon wavelength of 1550 nm is 93%. This performance was attained from a superconducting nanowire single-photon detector made of amorphous WSi; such detectors are usually operated at sub-Kelvin temperatures. In this study, we first demonstrate superconducting nanowire single-photon detectors made of polycrystalline NbN with system detection efficiency of 90.2% for 1550-nm-wavelength photons at 2.1 K, accessible with a compact cryocooler. The system detection efficiency saturated at 92.1% when the temperature was lowered to 1.8 K. We expect the results lighten the practical and high performance superconducting nanowire single-photon detectors to quantum information and other high-end applications. 相似文献
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We have studied supercurrent-assisted formation of the
resistive state in nano-structured disordered superconducting
Nb(N) films after absorption of a single optical to near-infrared
photon. The efficiency of the resistive state formation has a
pronounced spectral cut-off; corresponding threshold photon energy
decreases with the bias current. Analysis of the experimental data
in the framework of the refined hot-spot model suggests that the
quantum yield for near-infrared photons increases with the photon
energy. Relaxation of the resistive state depends on the photon
energy making the phenomena feasible for the development of energy
resolving single-photon detectors. 相似文献
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A. Casaburi M. Ejrnaes F. Mattioli A. Gaggero R. Leoni N. Martucciello S. Pagano M. Ohkubo R. Cristiano 《Journal of nanoparticle research》2011,13(11):6121-6131
The recent progress in the nanofabrication of superconducting films opens the road toward detectors with highly improved performances.
This is the case for superconducting nano-striplines where the thickness and the width are pushed down to the extreme limits
to realize detectors with unprecedented sensitivity and ultra fast response time. In this way quantum detectors for single
photons at telecommunication wavelengths and for macromolecules such as proteins can be realized. As is often the case in
applied nanotechnology, it is a challenge to make devices with the necessary macroscopic dimensions that are needed to interface
present technologies, while maintaining the performance improvements. For nano-stripline detectors, both the fast temporal
response and the device sensitivity is generally degraded when the area is increased. Here, we present how such detectors
can be scaled up to macroscopic dimensions without losing the performance of the nano-structured active elements by using
an innovative configuration. In order to realize ultrathin superconducting film the nano-layer is growth with a careful setup
of the deposition technique which guarantees high quality and thickness uniformity at the nano-scale size. The active nano-strips
are defined with the state-of-the-art electron beam nanolithography to achieve a highly uniform linewidth. We present working
detectors based on nano-strips with thicknesses 9–40 nm and widths of 100–1000 nm which exhibit unprecedented speed and area
coverage (40 × 40 μm2 for single photon detectors and 1 × 1 mm2 for single molecule detectors) based on niobium nitride thus enabling practical use of this nanotechnology. 相似文献
11.
V. A. Gaisler 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(1):77-79
Single-photon emitters based on semiconductor quantum dots are briefly reviewed. A design of an single-photon electrically
driven emitter containing a single InAs quantum dot and a Bragg microcavity is analyzed. It is shown that the external quantum
efficiency of such emitters can be as high as 78%.
Original Russian Text ? V.A. Gaisler, 2009, published in Izvestiya Rossiiskoi Akademii Nauk. Seriya Fizicheskaya, 2009, Vol.
73, No. 1, pp. 83–86. 相似文献
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Pinshu Rui Wen Zhang Yanlin Liao Ziyun Zhang 《International Journal of Theoretical Physics》2016,55(11):4798-4808
By utilizing the quantum parity-check detectors (PCDs) based on the weak cross-Kerr nonlinearities, we propose a scheme for realizing the remote quantum information concentration (RQIC) with the quantum channel of four-photon bound entangled state. After the PCDs and single-photon operations, quantum information initially distributed in three spatially separated photons is concentrated back to a single photon without performing any global operations. The success probability of the scheme is almost a unit. The necessary single-photon unitary operations corresponding to possible measurement outcomes are given detailedly. 相似文献
13.
Finite-key analysis of practical time-bin high-dimensional quantum key distribution with afterpulse effect
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High-dimensional quantum resources provide the ability to encode several bits of information on a single photon, which can particularly increase the secret key rate rate of quantum key distribution (QKD) systems. Recently, a practical four-dimensional QKD scheme based on time-bin quantum photonic state, only with two single-photon avalanche detectors as measurement setup, has been proven to have a superior performance than the qubit-based one. In this paper, we extend the results to our proposed eight-dimensional scheme. Then, we consider two main practical factors to improve its secret key bound. Concretely, we take the afterpulse effect into account and apply a finite-key analysis with the intensity fluctuations. Our secret bounds give consideration to both the intensity fluctuations and the afterpulse effect for the high-dimensional QKD systems. Numerical simulations show the bound of eight-dimensional QKD scheme is more robust to the intensity fluctuations but more sensitive to the afterpulse effect than the four-dimensional one. 相似文献
14.
S. A. Podoshvedov 《Journal of Experimental and Theoretical Physics》2008,106(3):435-441
We study a teleportation protocol of an unknown macroscopic qubit by means of a quantum channel composed of the displaced
vacuum and single-photon states. The scheme is based on linear optical devices such as a beam splitter and photon number resolving
detectors. A method based on conditional measurement is used to generate both the macroscopic qubit and entangled state composed
from displaced vacuum and single-photon states. We show that such a qubit has both macroscopic and microscopic properties.
In particular, we investigate a quantum teleportation protocol from a macroscopic object to a microscopic state.
The text was submitted by the author in English. 相似文献
15.
超导体的发现距今已有近110年了,高温超导体的发现也已经有30多年了.超导材料的电子学应用在最近一二十年取得了突破性进展.高温超导微波器件显示了比传统微波器件更优越的性能,已经在移动通信、雷达和一些特殊通信系统中取得了规模化应用.超导量子干涉器件以其磁场和电流测量的超高灵敏度,成为地质勘探、磁共振成像和生物磁成像等领域不可替代的手段.包括超导隧道结混频器、超导热电子混频器、超导转变沿探测器及超导单光子探测器等在内的超导传感器/探测器可以探测全波段的电磁波及各种宇宙辐射,具有接近量子极限的超高灵敏度,在地球物理、天体物理、量子信息技术、材料科学及生物医学等众多前沿领域发挥越来越重要的作用.超导参量放大器已经成为实现超导量子计算的关键器件.超导集成电路技术已被列入国际器件与系统技术路线图,成为后摩尔时代微电子领域的前沿阵地之一.在计量科学中,超导约瑟夫森效应及约瑟夫森结阵器件被广泛应用于量子电压基准和国际单位制基本单位的重新定义中.在当前的量子信息技术热潮中,超导电子学扮演重要角色,同时量子热潮也大力推动了超导电子学的发展.本文主要对近几年我国超导电子学研究和应用的现状与进展进行概括总结. 相似文献
16.
Quantum transducers can transfer quantum information between different systems. Microwave–optical photon conversion is important for future quantum networks to interconnect remote superconducting quantum computers with optical fibers. Here, a high-speed quantum transducer based on a single-photon emitter in an atomically thin membrane resonator, that can couple single microwave photons to single optical photons, is proposed. The 2D resonator is a freestanding van der Waals heterostructure (which may consist of hexagonal boron nitride, graphene, or other 2D materials) that hosts a quantum emitter. The mechanical vibration (phonon) of the 2D resonator interacts with optical photons by shifting the optical transition frequency of the single-photon emitter with strain or the Stark effect. The mechanical vibration couples to microwave photons by shifting the resonant frequency of an LC circuit that includes the membrane. Thanks to the small mass of the 2D resonator, both the single-photon optomechanical coupling strength and the electromechanical coupling strength can reach the strong coupling regime. This provides a way for high-speed quantum state transfer between a microwave photon, a phonon, and an optical photon. 相似文献
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Solid-state sources of single-photon emitters are highly desired for scalable quantum photonic applications, such as quantum communication, optical quantum information processing, and metrology. In the past year, great strides have been made in the characterization of single defects in wide-bandgap materials, such as silicon carbide and diamond, as well as single molecules, quantum dots, and carbon nanotubes. More recently, single-photon emitters in layered van der Waals materials attracted tremendous attention, because the two-dimensional(2 D)lattice allows for high photon extraction efficiency and easy integration into photonic circuits. In this review, we discuss recent advances in mastering single-photon emitters in 2 D materials, electrical generation pathways,detuning, and resonator coupling towards use as quantum light sources. Finally, we discuss the remaining challenges and the outlooks for layered material-based quantum photonic sources. 相似文献
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Y. B. Sheng F. G. Deng B. K. Zhao T. J. Wang H. Y. Zhou 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(1):235-242
We present a scheme for multipartite entanglement purification of
quantum systems in a Greenberger-Horne-Zeilinger state with quantum
nondemolition detectors (QNDs). This scheme does not require the
controlled-not gates which cannot be implemented perfectly with
linear optical elements at present, but QNDs based on cross-Kerr
nonlinearities. It works with two steps, i.e., the bit-flipping
error correction and the phase-flipping error correction. These two
steps can be iterated perfectly with parity checks and simple
single-photon measurements. This scheme does not require the parties
to possess sophisticated single photon detectors. These features
maybe make this scheme more efficient and feasible than others in
practical applications. 相似文献