Squeezing and amplitude-squared squeezing effects on the dynamics of two nonidentical two-level Squeezing and amplitude-squared squeezing effects on the dynamics of two nonidentical two-level atoms atoms

Amplitude-squared squeezing of Schrödinger cat states via Postselected von Neumann Measurement

We know that the original Schrödinger cat states has no amplitude-squared squeezing. In this paper, we investigate the amplitude-squared squeezing of Schrödinger cat states using postselected von Neumann measurement. The results show that after postselected von Neumann measurement, the amplitude-squared squeezing of Schrödinger cat states change dramatically and this can be considered a result of weak value amplification. The squeezing effect also investigated by studying the Wigner function of Schrödinger cat states after postselected measurement.

A squeezing invariant measurement to test displacement of quantum Gaussian states

We consider a hypothesis testing problem for displacement parameters of n independent copies of an m-mode squeezed quantum Gaussian state whose mixture parameter is known. Given n>1, we construct a quantum measurement as a test using an observable which is invariant by n-fold tensor product of any m-mode squeezing operator. For a pure state case, we calculate the type II error probability of this test. We compare this test with a Hotelling's T-squared test which is based on heterodyne measurements.

Studying the squeezing effect and phase space distribution of single-photon-added coherent state using postselected von Neumann measurement

In this paper, ordinary and amplitude-squared squeezing as well as Wigner functions of single-photon-added coherent state after postselected von Neumann measurements are investigated. The analytical results show that the von Neumann type measurement which is characterized by post-selection and weak value can significantly change the squeezing feature of single-photon-added coherent state. It is also found that the postselected measurement can increase the nonclassicality of the original state in strong measurement regimes. It is anticipated that this work could may provide an alternate and eff…

Schrödinger Intelligent States and Linear and Quadratic Amplitude Squeezing

A complete set of solutions |z,u,v>_{sa} of the eigenvalue equation (ua^2+va^{dagger 2})|z,u,v> = z|z,u,v> ([a,a^{dagger}]=1) are constructed and discussed. These and only these states minimize the Schrödinger uncertainty inequality for the squared amplitude (s.a.) quadratures. Some general properties of Schrödinger intelligent states (SIS) |z,u,v> for any two observables X, Y are discussed, the sets of even and odd s.a. SIS |z,u,v;+,-> being studied in greater detail. The set of s.a. SIS contain all even and odd coherent states (CS) of Dodonov, Malkin and Man'ko, the Perelomov SU(1,1) CS and …

具有不同参数的新型偶数和奇数非线性相干态的性质

Properties of new even and odd nonlinear coherent states with different parameters

本文通过引入更一般的非线性函数构造新型偶数和奇数非线性相干态，研究其非经典性质，发现偶数态呈现光子聚束效应、奇数态呈现反聚束效应，且压缩程度受参数影响，为实验提供理论依据。

Superposition of two nonlinear coherent states $\fracπ{2}$ out of phase and their nonclassical properties

Considering the concept of "{\it nonlinear coherent states}", we will study the interference effects by introducing the {\it "superposition of two classes of nonlinear coherent states"} which are $\fracπ{2}$ out of phase. The formalism has then been applied to a few physical systems as "harmonious states", "SU(1,1) coherent states" and "the center of mass motion of trapped ion". Finally, the nonclassical properties such as sub-Poissonian statistics, quadrature squeezing, amplitude-squared squeezing and Wigner distribution function of the superposed states have been investigated, numerically. E…