A scheme for teleporting Schridinger-cat states via the dispersive atom-cavity-field interaction

A proposal is presented for teleporting Schr*iding-cat states. The process of the teleportation is achieved through the dispersive atom-cavity-field interaction. In this proposal, only measurement on the cavity field and on the singlet atomic states are used.

光纤孤子的量子特性:压缩态和类薛定谔猫态(Schrdinger-cat-like states)

利用与时间有关的Hartree近似法证明借助非线性Mach-Zehnder干涉仪可以得到光孤子的光子数压缩态<(Δ^N)2>min～<^N>1/3,并且指出在一些特定时刻光纤孤子会呈现出类薛定谔猫态(Schr dinger-cat-likestates)。

双光子Jaynes-Cummings模型中的Schrdinger-Cat态及其演化特性

文章采用密度算符间的距离充分论证了双光子Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ模型在初始相干光场较强时（ｎ》１）在某些特定时刻（ｇｔ＝（２ｍ＋１）π４，ｍ＝０，１，２，…）腔场演化为振幅相同而位相差为π２或３２π的两个相干态的叠加态，即Ｓｃｈｒｄｉｎｇｅｒ－Ｃａｔ态，给出了Ｓｃｈｒｄｉｎｇｅｒ－Ｃａｔ态的演化图象。

Nonreciprocal generation of Schrodinger cat state induced by topology

The Schrodinger cat state produced differently in two directions is anticipated to be a critical quantum resource in quantum information technologies.By exploring the interplay between quantum nonreciprocity and topology in a one-dimensional microcavity array,we obtain the Schrodinger cat state(a pure quantum state)in a chosen direction at the edge cavity,whereas a classical state in the other direction.This nonreciprocal generation of the cat state originates from the topologically protected chiralitymode excitation in the nontrivial phase,but in the trivial phase,the nonreciprocal generation of cat state vanishes.Thus,our proposal is switchable by tuning the parameters so that a topological phase transition occurs.Moreover,the obtained cat state has nonreciprocal high fidelity,nonclassicality,and quantum coherence,which are sufficient to be used in various one-way quantum technologies,e.g.,invisible quantum sensing,noise-tolerant quantum computing,and chiral quantum networks.Our work provides a general approach to control quantum nonreciprocities with the topological effect,which substantially broadens the fields of nonreciprocal photonics and topological physics.

Schrödinger’s Cat Paradox Resolution Using GRW Collapse Model: Von Neumann Measurement Postulate Revisited

In his famous thought experiment, Schr?dinger (1935) imagined a cat that measures the value of a quantum mechanical observable with its life. Since Schr?dinger’s time, no any interpretations or modifications of quantum mechanics have been proposed which give clear unambiguous answers to the questions posed by Schr?dinger’s cat of how long superpositions last and when (or whether) they collapse? In this paper appropriate modification of quantum mechanics is proposed. We claim that canonical interpretation of the wave function is correct only when the supports of the wave functions and essentially overlap. When the wave functions and have separated supports (as in the case of the experiment that we are considering in this paper) we claim that canonical interpretation of the wave function is no longer valid for a such cat state. Possible solution of the Schr?dinger’s cat paradox is considered. We pointed out that the collapsed state of the cat always shows definite and predictable outcomes even if cat also consists of a superposition: .

V型三能级原子与双模光场相互作用的演化及Schrdinger猫态的制备

详细研究了一个V型三能级原子与双模光场的相互作用。结果表明 :在原子与场的失谐量较大的情况下 ,基态能级可被绝热消除 ,从而把这一模型简化为一个等效的二能级原子与双模场相互作用的非简并Raman耦合模型 ,分别得出了非简并Raman耦合模型和简并Raman耦合模型系统的改进型有效哈密顿量和波函数。在此基础上通过对腔中原子进行选态测量 ,提出一种由具有可控权重因子和位相的相干叠加态组成的制备Schr

制备多模Schrdinger猫态的一种新方案

提出一种制备多模相干态的叠加态，即Ｓｃｈｒ ｄｉｎｇｅｒ猫态的方案．在这个方案中，一个Ｖ型三能级原于被注入多个处于相干态的腔．通过Ｒａｍａｎ相互作用，使整个系统处于纠缠状态，然后对原子进行探测，则腔场组成系统将坍缩到多模 Ｓｃｈｒ■ｄｉｎｇｅｒ猫态．在一定的条件下，这个猫态等同于一个ＧＨＺ（Ｇｒｅｅｎｂｅｒｇｅｒ－Ｈｏｒｎｅ－Ｚｅｉｌｉｎｇｅｒ）态，可用来检验局域理论．

两态叠加Schrdinger猫态光场的两种测不准态

根据多模压缩态理论,详细研究了两态叠加Schr¨odinger猫态光场的压缩特性.发现:在一定的条件下,该光场将不呈现等幂次的Y和H压缩效应以及等幂次的N-Y和N-H最小测不准态;而呈现出等幂次的N-Y测不准态和N-H测不准态.

Optomechanical Schrödinger cat states in a cavity Bose-Einstein condensate

Schrödinger cat states,consisting of superpositions of macroscopically distinct states,provide key resources for a large number of emerging quantum technologies in quantum information processing.Here we propose how to generate and manipulate mechanical and optical Schrödinger cat states with distinguishable superposition components by exploiting the unique properties of cavity optomechanical systems based on Bose-Einstein condensate.Specifically,we show that in comparison with its solid-state counterparts,almost a 3 order of magnitude enhancement in the size of the mechanical Schrödinger cat state could be achieved,characterizing a much smaller overlap between its two superposed coherent-state components.By exploiting this generated cat state,we further show how to engineer the quadrature squeezing of the mechanical mode.Besides,we also provide an efficient method to create multicomponent optical Schrödinger cat states in our proposed scheme.Our work opens up a new way to achieve nonclassical states of massive objects,facilitating the development of fault-tolerant quantum processors and sensors.

一类关联双模Schrdinger描态的制备

本文研究了Ⅴ型三能级原子与一个双模光场的共振相互作用，并讨论了在任意依赖强度耦合的多光子情况下的一类关联双模Schrodinger描态的制备．

Properties and Generation of Photon-Added Schrdinger Cat States

We have investigated the intensity squeezing of superposition of two photon-added coherent states and proposed a new method for preparation of photon-added coherent states and their superposition states.This method is based on interaction of the trapped ion with the traveling wave light fields with different frequencies.

多模薛定谔猫态光场的高次差压缩效应

构造了由多模复共轭相干态、多模复共轭虚相干态、多模真空态线性叠加组成的多模叠加薛定谔猫态光场.利用多模压缩态理论,研究了该猫态光场的任意次广义非线性等幂次高次差压缩特性.结果表明,多模叠加薛定谔猫态光场中的真空场对其差压缩特性无直接影响;在一定条件下,该猫态光场的两个正交相位分量可分别呈现出等幂次高次差压缩效应;而在另外的条件下,该猫态光场的两个正交相位分量可同时呈现出等幂次高次差压缩效应,这是一种相悖于海森堡测不准关系的新物理现象.

MSCS光场广义非线性不等幂次差压缩特性研究

利用多模辐射场的广义非线性不等幂次差压缩的一般理论 ,研究了具有普遍意义的两态叠加多模薛定谔猫态 (MSCS)光场的广义非线性不等幂次差压缩特性 (即Nj 次方X压缩特性 ) .通过计算 ,求得了MSCS的Nj 次方X压缩的一般理论结果 ,为寻找压缩条件提供了理论依据 .

存在内禀退相干时薛定谔猫态光场中原子的布居数反转

通过求解系统的Milburn方程,研究了二能级原子与薛定谔猫态光场相互作用系统中原子的布居数反转.分析了内禀退相干、光场强度、相干态间的相位角对原子布居数反转的影响.结果表明,当存在内禀退相干时,原子布居数反转随着时间的演化,逐渐衰减为零.光场强度不变时,随着内禀退相干因子的减小,原子布居数反转衰减加剧,其中奇相干态光场中原子布居数反转的衰减速度较快;偶相干态光场中原子布居数反转的衰减速度较慢;Yurke-Stoler相干态光场中原子布居数反转的变化情形介于其中.内禀退相干因子不变时,随着光场强度的增加,出现崩塌-恢复现象,并且Rabi振荡的包络值很快衰减为零.

Ξ型原子与腔场的非共振作用实现量子逻辑门与猫态的传送

提出了利用Ξ型三能级原子与腔场的非共振相互作用产生原子腔场纠缠态 ,并实现量子逻辑非门及薛定谔猫态的隐形传送 .

一种薛定谔猫态的量子统计性质

对薛定谔猫态 |α〉c 的非经典性质进行了研究 ,用数值计算的方法讨论了它的压缩性质。

非线性光学的量子效应

简要地论述单模非经典光场的普适判据,提出两种产生光子数压缩态的途径,以及证明奇、偶相干态实际上是种宏观可识别的量子迭加态(即薛定谔猫)。

利用Raman相互作用制备双模SU(2)薛定谔猫态

首先将腔场制备成双模SU(2 )态 ,然后不断注入与腔场发生Raman相互作用的V型三能级原子 ,通过原子—腔场相互作用生成腔场—原子纠缠 ,依次通过对原子进行选择性测量 ,利用波包塌缩原理 ,即可获得双模SU(2 )场纠缠态。

运动原子和不同初始场相互作用系统中熵和纠缠的研究(英文)

通过计算线性熵研究了当场初始处于薛定谔猫态和压缩相干态时Jaynes-Cummings模型中原子线性熵随时间的演化特性,讨论了原子运动和场模结构参数对原子线性熵的影响.结果发现原子和场之间的纠缠对压缩参数非常敏感,并且结果表明当腔场初始处于Yurke-Stoler态时,原子的运动导致了线性熵的周期性演化,随着场模结构参数的增加,不但线性熵的演化周期缩短,而且线性熵的的幅值减小.当腔场初始处于偶相干态时,场模结构参数的增加导致了线性熵的演化周期缩短,然而对线性熵的幅值没有影响.

多模SCS光场中广义电场的不等幂次高次和压缩

根据量子力学中态的线性叠加原理,构造了由多模复共轭虚相干态、多模复共轭虚相干态的相反态和多模复共轭相干态的线性叠加所组成的三态叠加多模振幅-相位混合Schrdinger-Cat(即SCS)光场│Ψ3〉q。利用新近建立的多模压缩态理论,对SCS光场│Ψ3〉q中广义电场分量的不等幂次高次和压缩特性进行了详细研究。结果发现:在各模的压缩次数之和取偶数的条件下,当各模的压缩次数与对应模的初始相位之积的和、态间的初始相位差、以及各多模相干态光场的平均光子数等分别满足一定的取值条件时,此三态叠加多模SCS光场│Ψ3〉q的广义电场分量总可呈现出周期性变化的任意Nj次的广义非线性不等幂次高次和压缩效应。