共查询到20条相似文献，搜索用时 15 毫秒
1.
利用双模压缩真空态实现量子态的远程传输 总被引：2，自引：0，他引：2
借助于双模压缩真空态在EPR纠缠态表象中的表示,研究了用双模压缩真空态作为量子通道 实现任意的单模和双模量子态的远程传输. 关键词：量子隐形传态EPR纠缠态压缩真空态 相似文献
2.
解析推导了任意光子扣除(增加)压缩真空态与压缩猫态的保真度. 研究表明,无论是光子增加还是光子扣除,最大保真度都随光子增加或扣除数目的增加而增加,且最大保真度对应的叠加态振幅也增加;此外,对于相同数目的增加和扣除光子数,光子增加后的最大保真度所对应的叠加态振幅比光子扣除所对应的叠加态振幅要大,而最大保真度略小一些. 尽管目前从实验上实现光子增加比光子扣除困难较大,但光子增加也可以成为获得大振幅猫态的一个有力手段.关键词：光子扣除压缩真空态光子增加压缩真空态压缩猫态保真度 相似文献
3.
Statistical properties of coherent photon-subtracted two-mode squeezed vacuum and its application in quantum teleportation 
下载免费PDF全文
下载免费PDF全文 We introduce a kind of non-Gaussian entangled state, which can be obtained by operating a non-local coherent photon-subtraction operation on a two-mode squeezed vacuum. It is found that its normalization factor is only related to the Legendre polynomials, which is a compact expression. Its statistical properties are discussed by the negative region Wigner function with the analytical expression. As an application, the quantum teleportation for coherent states is considered by using the non-Gaussian state as an entangled channel. It is found that the teleportation fidelity can be enhanced by this non-Gaussian operation. 相似文献
4.
We propose a nearly perfect optical scheme for the quantum teleportation ofentangled coherent states using optical devices such as nonlinear Kerr media, beamsplitters, phase shifters, and photon detectors. Different from those previousschemes, our scheme needs only ``yes' or `no' measurements of the photon number ofthe related modes, i.e. nonzero- and zero-photon measurements, while in previousschemes one has to exactly identify the even or odd parity character of the photonnumbers detected by detectors. 相似文献
5.
This paper presents a realistic scheme for the teleportation ofcoherent states in which a two-mode squeezed vacuum state serves asthe quantum channel and the position-sum and momentum-difference oftwo local modes serve as the measuring observables. The averagefidelity of the teleportation of coherent states is derived forfinite squeezing parameters and it turns out that fidelity greaterthan 1/2 cannot be achieved by using a classical channel alone andthe probability distribution of the measurement result is a Gaussiandistribution around the unknown parameter of the input coherentstate with a width given by the squeezing parameter. 相似文献
6.
The proposals on entanglement diversion and quantum teleportation ofentangled coherent states are presented.In these proposals, the entanglement between two coherent states, $|alpharangle$ and $|-alpharangle$, with the same amplitude but a phase differenceof $pi$ is utilized as a quantum channel. The processes of the entanglement diversion and the teleportation are achieved by using the 50/50 symmetric beam splitters, the phase shifters and the photodetectors with the help of classical information. 相似文献
7.
在压缩真空态光场和二能级原子玻色-爱因斯坦凝聚体相互作用系统中, 应用全量子理论, 采用非旋波近似, 研究了光场的压缩特性以及原子本征频率、原子-光场的耦合系数、光场初始压缩因子以及虚光场对系统光场压缩特性的影响. 研究表明, 光场的两个正交分量均被周期性压缩, 其压缩深度与光场初始压缩因子有关, 光场与原子的耦合系数决定了光场的量子崩塌-回复频率,虚光场效应使得光场的压缩深度增强. 相似文献
8.
Interference metrology is a method for achieving high precision detection by phase estimation. The phase sensitivity of a traditional interferometer is subject to the standard quantum limit, while its resolution is constrained by the Rayleigh diffraction limit. The resolution and sensitivity of phase measurement can be enhanced by using quantum metrology. We propose a quantum interference metrology scheme using the entangled squeezed vacuum state, which is obtained using the magic beam splitter, expressed as |ψ〉=(|ξ〉|0〉+|0〉|ξ〉)/(2+2/coshr)~(1/2), such as the N00 N state. We derive the phase sensitivity and the resolution of the system with Z detection, project detection, and parity detection. By simulation and analysis, we determine that parity detection is an optimal detection method, which can break through the Rayleigh diffraction limit and the standard quantum limit. 相似文献
9.
《中国物理 B》2021,30(7):74202-074202
The precision measurement of Doppler frequency shifts is of great significance for improving the precision of speed measurement. This paper proposes a precision measurement scheme of tiny Doppler shifts by a parametric amplification process and squeezed vacuum state. This scheme takes a parametric amplification process and squeezed vacuum state into a detection system, so that the measurement precision of tiny Doppler shifts can exceed the Cram′er–Rao bound of coherent light. Simultaneously, a simulation study is carried out on the theoretical basis, and the following results are obtained: for the signal light of Gaussian mode, when the amplification factor g = 1 and the squeezed factor r = 0.5, the measurement error of Doppler frequency shifts is 14.4% of the Cramer–Rao bound of the coherent light in our system. At the same time,when the local light mode and squeezed vacuum state mode are optimized, the measurement precision of this scheme can be further improved by ■ times, where n is the mode-order of the signal light. 相似文献
10.
连续变量量子离物传态的实验研究 总被引：1，自引：0，他引：1
利用单个Ⅱ类相位匹配OPA产生的双模压缩态实现连续变量压缩纠缠态,完成了连续变量量 子离物传态. Ⅱ类相位匹配OPA参量反放大过程可以实现正交振幅反关联、正交位相关联的 压缩纠缠态,这不同于一般运转于阈值以下的OPO产生的正交振幅关联、正交位相反关联的 压缩纠缠态,可以采用直接平衡测量的方法完成Bell态测量. 利用双KTP补偿非线性过程的 离散效应,获得了最大压缩大于2dB的双模压缩纠缠态,实现保真度06,考虑到探测效率 实际保真度为057. 这种方案简化了测量方法与纠缠光源产生装置,有利于进行量子通信 的实验研究与应用. 同时,讨论了探测过程中的一些非理想因素.关键词：量子离物传态压缩纠缠态Bell态测量 相似文献
11.
We present a scheme to prepare cluster-type entangled squeezed vacuum states （CTESVS） by considering the two-photon interaction between a two-level atom and a high-quality cavity, driven by a strong classical field. After the realization of simple atomic measurements, the generation of CTESVS in four separate cavities is accomplished within the cavity decay time. In the case of large atom=cavity detuning, the scheme is immune to the effect of atomic spontaneous emission. 相似文献
12.
We study the one-and two-mode photon distribution functions for Gaussian quantum states. The dependence on the photon-quadrature
parameters is discussed within the framework of violation of the uncertainty relation. We derive the one-and two-mode photon
distribution functions and present plots demonstrating that the expressions for the distribution functions take negative or
complex values in the domain of quadrature parameters violating the uncertainty relation. 相似文献
13.
提出一个量子隐形传态的新方案. 通过对一对压缩参数相同但相互独立的双模压缩真空态(1-2和3-4量子态系统)中的2-3系统施行粒子数-相位的联合测量,制备出另外两体系统(1-4系统)的纠缠态作为纠缠源,从而实现量子隐形传态.关键词：量子隐形传态双模压缩真空态纠缠态粒子数-相位测量 相似文献
14.
介观无损耗传输线中电流的量子涨落 总被引：5，自引：2，他引：5
在将介观无损耗传输线量子化的基础上, 研究了真空态和压缩真空态下传输线中电流和电流梯度的量子涨落. 着重分析了传输线与一般LC电路量子涨落的差异.关键词：介观无损耗传输线真空态压缩真空态量子涨落 相似文献
15.
A new bipartite coherent-entangled state is introduced in the two-mode Fock space, which exhibits the properties of both a coherent state and an entangled state. The set of coherent-entangled states makes up a complete and partly nonorthogonal representation. A simple experimental scheme to produce the coherent-entangled state using an asymmetric beamsplitter is proposed. Some applications of the coherent-entangled state in quantum optics are also presented. 相似文献
16.
Based on the fact that a two-mode squeezed number state is atwo-variable Hermite polynomial excitation of the two-mode squeezedvacuum state, the result of one-mode l-photon measurement for thetwo-mode squeezed number state $S_2|m,nrangle$ is discussed. It is found that a remaining field-mode simultaneouslycollapses into a number state $|n-m+lrangle$ withthe coefficient being a Jacobi polynomial of n, m and l, which manifestly exhibits the entanglementbetween the two modes, i.e. it depends on the number-differencebetween the two modes. The second mode collapses into an excitedcoherent state when the first mode is measured as a coherent state. 相似文献
17.
A new bipartite coherent-entangled state is introduced in the two-mode Fock space,which exhibits the properties of both a coherent state and an entangled state.The set of coherent-entangled states makes up a complete and partly nonorthogonal representation.A simple experimental scheme to produce the coherent-entangled state using an asymmetric beamsplitter is proposed.Some applications of the coherent-entangled state in quantum optics are also presented. 相似文献
18.
介观耗散LC并联电路的量子效应 总被引：9，自引：1，他引：9
对介观耗散LC并联电路作阻尼谐振子处理,将其量子化。在此基础上,研究了Fock态及压缩真空态下,介观耗散LC并联电路中各支路电流和电压的量子涨落。结果表明,各支路电流电压的量子涨落均与电路器件的固有参数及所选量子态有关。 相似文献
19.
FAN Hong-Yi LIANG Xian-Ting 《理论物理通讯》2005,44(5):833-836
A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement is feasible because the bipartite entangled states are complete and the squeezed state has a natural representation in the entangled state basis. The calculation is greatly simplified by using the Schmidt decomposition of the entangled states. 相似文献
20.
A scheme is proposed to generate an N-qubit cluster-type entangled squeezed vacuum state （CTESVS） based on the two-photon interaction between a two-level atomand the cavity fields with the cavity QED system. The CTESVS in N separate cavities can be effectively obtained after performing a simple one-qubit measurement on the atom. The influence of cavity decay on the CTESVS is also discussed. 相似文献