利用腔量子电动力学方法实现压缩叠加态的量子隐形传态(英文)

利用大失谐的原子 -腔场相互作用和Bell态测量 ,提出了一个量子隐形传态方案。在这个方案中 ,两个具有相同振幅和相对位相的压缩真空态的任意相干叠加态被传送。为了实现这个方案 ,一个最大纠缠压缩真空态被用来作为量子信道。这个量子隐形传态方案成功的几率是 0 .5。

叠加激发双模压缩真空态的量子统计特性(英文)

从激发双模压缩真空态 a mb m| ξ〉出发构造了叠加态 | Ψ〉,研究了 | Ψ〉的量子统计特性 .结果表明 :在一定的条件下 ,随着相位差的变化 ,叠加态 | Ψ〉的平均光子数出现类似于Rabi振荡的崩塌与复原现象 ,而且与单个激发双模压缩真空态 a mb m|ξ〉相比 ,在叠加态

原子系综双模压缩叠加相干态的制备和性质

提出了一个在双模腔中制备原子系综双模压缩叠加相干态的方案.此外,还讨论了所制备态的非经典性质.结果表明,双模压缩相干叠加态具有更强的非经典性质.

叠加相干态与叠加压缩态的相位精度研究

利用Cramér-Rao下界法计算了叠加相干态与叠加压缩态可以达到的最优相位精度。结果表明,平均粒子数较大时,叠加相干态的精度只能达到标准量子极限,而叠加压缩态精度更高,达到了海森伯格极限。应用损耗模型,分析了二态在有损信道中传输所受到的影响。研究显示2种量子态的精度都会有所下降。最后又加入了相干态与压缩态,将4种量子状态进行比较。比较结果显示,当各态平均粒子数较大时,压缩态与叠加压缩态精度较高。当平均粒子数较小时,随着损耗的增加,叠加压缩态对外界环境的影响显得很敏感,其精度衰减得更快些。

叠加压缩相干态的量子统计性质

研究了叠加压缩相干态的量子统计性质,给出了压缩和反聚束效应与叠加系数之间的关系。结果表明,叠加压缩相干态具有压缩和反聚束的现象。压缩奇偶相干态的有关结果均作为特例包含在本文的一般结论之中。

双模压缩叠加相干态的非经典性质

本文描述辐射场的一类新的非经典态,称之为双模压缩叠加相干态,其定义式为:|φ〉=CS(ξ)(|1α,2α〉+eiφ|1α*,α2*〉).通过它的归一化常数的计算,讨论其非经典性质,即压缩效应、亚泊松分布、光子反聚束效应以及两模间二阶相关函数。数值计算结果表明,双模压缩叠加相干态具有更为显著的非经典性质,只要我们适当地选择参数1α,2α,φ,θ和ξ,双模压缩叠加相干态就可以约化成双模压缩叠加真空态和双模叠加相干态,因此双模压缩叠加相干态是更广泛的一类非经典光场态。

Realization of superposition and entanglement of coherent and squeezed states in circuit quantum electrodynamics

We propose a new scheme for generating the superposition and entanglement of the coherent states and squeezed states by consid- ering N superconducting charge qubits （or artificial two-level atoms） interacting with photons in a high finesse cavity on a chip, assisted by a strong driving field. By virtue of the parameters of this system, we can generate novel quantum states, for example, multiparty entangled states and Schr6dinger cat states among the superconducting qubits, coherent states and squeezed states of the cavity. These states, whose amplitudes are about two orders greater than those from the atomic quantum electrodynamics in classical cavity, are important for understanding the boundary between quantum and classical behavior and can be utilized in experimental studies on decoherence. This device may be an architecture for future solid-state quantum computation and communication.

f-Deformed Squeezed Vacuum and First Excited States, Their Superposition and Corresponding Nonclassical Properties

In this paper, we introduce two new classes of nonlinear squeezed states that we name as f-deformed squeezed vacuum state|ξ, f even and f-deformed squeezed first excited state |ξ, f odd, which according to their production processes, essentially include only even and odd bases of Fock space, respectively. In the continuation, we introduce the superposition of these two distinct nonlinear squeezed states with a respective phase ?. Then, some of the criteria which imply the nonclassicality of the states, such as Mandel parameter, second-order correlation function, quadrature squeezing, amplitude-squared squeezing, Husimi and Wigner–Weyl quasi-distribution functions, are numerically examined. At last, by considering a well-known nonlinearity function associated with a nonlinear physical system, we present our results which outcome from the numerical calculations. It is shown that, the introduced f-deformed states can reveal high nonclassical features.

Accuracy for superposition of squeezed states in lossless and dissipative channel

The analysis of accuracy for superposition of squeezed states （SSSs） in lossless and loss case has been performed in this study. In lossless case, time accuracies of SSSs with mean photon number ns have a scaling of ns-2 in two limits of large and small squeezing. With the help of photon loss model, the dissipative channel will degrade accuracies has been proved. In the limit of large squeezing, the accuracy will slowly decrease with the reduction of transmittance η. In the limit of small squeezing, time accuracy scales as 1/（η4n2） and will decrease much faster along with η decreases.