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arXiv 1402.4339cond-mat.quant-gas
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宏观极化子旋量环凝聚中自旋翻转的半涡旋

Spin-Flipping Half Vortex in a Macroscopic Polariton Spinor Ring Condensate

Gangqiang Liu, David W. Snoke, Andrew Daley, Loren Pfeiffer, Kenneth West

摘要:

本文报道了在环形几何中极化激元的宏观玻色-爱因斯坦凝聚体中的涡旋现象。由于它是一个旋量凝聚体,基元激发是“半涡旋”,其中有一个相位旋转$π$与一个偏振矢量旋转$π$围绕一个封闭的路径。这是清楚地看到在实验中观察到的偏振旋转周围的环。在环几何中,允许一种新型的半涡旋,其中自旋的旋向从环的一侧翻转到另一侧,除了线偏振分量的旋转之外;这种状态在简单连接的几何中是不允许的。对该状态能量的理论计算表明,当考虑多体相互作用时,它的能量比简单的半涡旋低。从一次发射到下一次发射,环周围流动的循环方向在顺时针和逆时针之间随机波动;这对应于系统中时间反演对称性的自发破缺。这些新的宏观极化激元环凝聚允许直接控制凝聚的涡度的可能性。

英文摘要:

We report the observation of vorticity in a macroscopic Bose-Einstein condensate of polaritons in a ring geometry. Because it is a spinor condensate, the elementary excitations are "half vortices" in which there is a phase rotation of $π$ in connection with a polarization vector rotation of $π$ around a closed path. This is clearly seen in the experimental observations of the polarization rotation around the ring. In the ring geometry, a new type of half vortex is allowed in which the handedness of the spin flips from one side of the ring to the other, in addition to the rotation of the linear polarization component; such a state is not allowed in a simply-connected geometry. Theoretical calculation of the energy of this state shows that when many-body interactions are taken into account, it is lower in energy than a simple half vortex. The direction of circulation of the flow around the ring fluctuates randomly between clockwise and counterclockwise from one shot to the next; this corresponds to spontaneous breaking of time-reversal symmetry in the system. These new, macroscopic polariton ring condensates allow for the possibility of direct control of the vorticity of the condensate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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