论文标题

增强了无序电势中自旋轨道耦合的玻色气体的运输

Enhanced transport of spin-orbit coupled Bose gases in disordered potentials

论文作者

Yue, Y., de Melo, C. A. R. Sá, Spielman, I. B.

论文摘要

安德森定位是无序介质中的单个粒子定位现象,伴随着没有扩散的情况。自旋轨道耦合(SOC)描述了粒子的自旋与其动量直接影响其能量分散的相互作用,例如与间隙和多个局部最小值建立分散关系。从理论上讲,我们证明了将一维自旋轨道耦合与横向zeeman场相结合,从而抑制了疾病的影响,从而增加了定位长度和电导率。这种增加是由于抑制了SOC分散关系间隙中状态之间的背部散射。在这里,我们专门关注来自光学斑点电位和由两光子拉曼过程产生的疾病相互作用,在准1D Bose-Einstein冷凝物中产生。我们首先使用费米的黄金法则方法来描述背部,然后通过求解时间依赖性的1d毛皮pitaevskii方程来数字确认这张图片,以使用SOC和疾病的弱相互作用的玻色 - 内斯坦冷凝物。我们发现,在典型的冷原子实验的10毫秒时尺度上,在谐波陷阱中移动,最初的状态在零摩托马特的SOC间隙中具有可忽略的背部散射,而没有SOC的情况下,这些状态迅速定位。

Anderson localization is a single particle localization phenomena in disordered media that is accompanied by an absence of diffusion. Spin-orbit coupling (SOC) describes an interaction between a particle's spin and its momentum that directly affects its energy dispersion, for example creating dispersion relations with gaps and multiple local minima. We show theoretically that combining one-dimensional spin-orbit coupling with a transverse Zeeman field suppresses the effects of disorder, thereby increasing the localization length and conductivity. This increase results from a suppression of back scattering between states in the gap of the SOC dispersion relation. Here, we focus specifically on the interplay of disorder from an optical speckle potential and SOC generated by two-photon Raman processes in quasi-1D Bose-Einstein condensates. We first describe back-scattering using a Fermi's golden rule approach, and then numerically confirm this picture by solving the time-dependent 1D Gross Pitaevskii equation for a weakly interacting Bose-Einstein condensate with SOC and disorder. We find that on the 10's of millisecond time scale of typical cold atom experiments moving in harmonic traps, initial states with momentum in the zero-momentum SOC gap evolve with negligible back-scattering, while without SOC these same states rapidly localize.

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