部分相干的高斯谢尔模物质波的轨道角动量

Twisted Property and Orbital Angular Momentum of GSM Matter Wave

部分相干物质波是处于临界温度以上的玻色冷原子气体。密度和一阶关联都满足高斯分布的部分相干物质波是高斯谢尔模(Gauss-Schell model)物质波。本文通过研究高斯谢尔模物质波一阶关联函数的相位结构,揭示出物质波在部分相干情况下的轨道角动量特点。证明扭曲相位是部分相干物质波具有的独特性质,完全相干物质波(如,玻色爱因斯坦凝聚体)不具有此相位。此外,本文举例分析了高斯谢尔模物质波在一个"柱透镜"光脉冲作用下,其轨道角动量的变化情况。

In this manuscript,the twisted property and orbital angular（OA）momentum of a partially coherent Gaussian-Schell mode（GSM）matter wave were investigated theoretically.A twist phase which produces OA,was proved to exist in the first correlation function of the GSM field.The appearance of this twist phase stems from the partial coherence of the matter wave field.The evolution of the twist-phase-OA in the GSM matter wave was studied with a tensor ABCD method.Benefiting from this tensor method,we derived an analytical formula for the evolution of the z-direction OA in the field of GSM matter wave.As an example,we analyzed the OA of a GSM matter wave under the action of one＂cylindrical lens＂optical pulse.By controlling the interaction direction of the optical pulse,the magnitude of OA can be designed.The theoretical formulas derived in this manuscript have potential applications in the OA production and manipulation in the field of partially coherent matter wave.