相位型三头薛定谔猫态的量子统计属性  

Quantum statistical properties of phase-type three-headed Schrodinger cat state

作　　者：林惇庆 朱泽群[1] 王祖俭[1] 徐学翔[1,2] 

机构地区：[1]江西师范大学物理与通信电子学院,南昌330022 [2]江西师范大学,量子科学与技术中心,南昌330022

出　　处：《物理学报》2017年第10期92-100,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11665013);江西省高等学校教学改革研究课题(批准号:JXJG-16-2-2);江西师范大学团队高原计划项目资助的课题~~

摘　　要：本文详细研究了一种相位型三头薛定谔猫态的一些量子统计属性,包括光子数分布、平均光子数、亚泊松分布、压缩效应以及Wigner函数等.我们发现,三头猫态的Wigner函数都可以出现负值,与二、四头猫态一样,说明它们都可以体现出非经典特性.与二头猫态不同,三头猫态在一定参数范围内可以呈现亚泊松分布,这点与四头猫态相类似,但弱于四头猫态.另外,三头猫态和四头猫态都没有压缩属性,但二头猫态具有压缩属性.Quantum superposition is a fundamental principle of quantum mechanics, which provides a crucial basis to observe phenomena beyond the predictions of classical physics. For example, a quantum entangled state can exhibit stronger correlation than classically possible one. In quantum state engineering, many new quantum states can be obtained from the superposition of many known states. In recent decades, the superposition of coherent states （CSs） with the same amplitude but two different phases has been a subject of great interest. This superposition state was often called Schrodinger cat state （here, we also name it 2-headed cat state （2HCS））, which becomes an important tool to study a lot of fundamental issues. Surprisingly, some studies have extended the quantum superposition to involving more than two component coherent states. In order to produce the superposition of three photons, people have considered the superposition of coherent states with three different phases （here, we also name it 3-headed cat state （3HCS））. Furthermore, in microwave cavity quantum electrodynamics of bang-bang quantum Zeno dynamics control, people have proposed the superposition of coherent states with four different phases （here, we also name it 4-headed cat state （4HCS））. In this paper, we make a detailed investigation on the quantum statistical properties of a phase-type 3HCS. These properties include photon number distribution, average photon number, sub-Poissionian distribution, squeezing effect, and Wigner function, etc. We derive their analytical expressions and make numerical simulations for these properties. The results are compared with the counterparts of the CS, the 2HCS and the 4HCS. The conclusions are obtained as follows. 1） The CS, the 2HCS, the 3HCS and the 4HCS have k, 2k, 3k and 4k photon number components, respectively （k is an integer）; 2） small difference in average photon number among these quantum states in small-amplitude range can be observed, while their average photon

关 键 词：薛定谔猫态 三头猫态 非经典性 WIGNER函数 

分 类 号：O413[理学—理论物理]