光子增加相干叠加态的Wigner函数

利用算符作用在参考态上产生新的量子态的方法 ,将产生算符作用在相干叠加态 上,构造了光子增加相干叠加态。给出了其归一化系数和Wigner函数的解析表达式。通过 数值计算,讨论了相干态平均光子数和两相干态的相位差对Wigner函数的影响。研究结果 表明,随两相干态的相位差增大,Wigner函数的负值深度和负值区域时而增大时而减小, 它的负部 体积随相位差的演化呈现出准周期性演化,表明选择合适的相位差值对增强量子态的量子特 性有利；另一方面,随相干态平均光子数逐渐增大,Wigner函 数的负部体积增大,表明光子增加相干叠加态的量子特性增强。

Wigner function of photon addition excited the superposition of coherent states

We introduce photon addition excited the superposition of coherent states (PASCT) by operation of photon addition on the superposition of coherent states with the sa me amplitude but two different phases.We derive the normalized constant of PASCT and its anal ytical expression of Wigner function.The influence of the average photon number of coherent stat e and phase difference on its Wigner function is investigated.The conclusions are obtained through numerical simulations as follows:The negative region and the negative depth of Wigner function of PASCT are sometimes strengthened and sometimes weakened with increase of th e phase difference,and the negative volume of Wigner function of PASCT displays quasi- periodic evolution with the phase difference.On the other hand,as the average photon nu mber in coherent state increases,the negative region and the negative depth of Wigner function ar e strengthened,and the negative volume of Wigner function of PASCT increases also,which implies th at its non-classicality is strengthened with the increase of the average phot on number.