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arXiv 2107.09385cond-mat.dis-nncond-mat.quant-gascond-mat.stat-mechnlin.CGquant-ph
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随机势中多体波包的对数展开

Logarithmic expansion of many-body wave packets in random potentials

Arindam Mallick, Sergej Flach

摘要:

安德森局域化将一维随机势中量子粒子的波函数限制在定域长度$ξ$数量级的体积内。非线性附加到波动力学模拟多体相互作用的平均场水平上,并导致从安德森笼逃逸,并在无限的subdiffusion的相互作用云。我们通过以下方式解决子扩散的量子校正:(i)使用离散时间量子行走的超快酉Floquet动力学,(ii)相互作用强度斜坡以加速子扩散,以及(iii)非线性项的动作离散化。我们观察到$N$粒子云膨胀到体积$\sim Nξ$的饱和。我们预测并观察到一个普遍的中间对数膨胀制度,连接平均场扩散与最终的饱和制度,完全由粒子数$N$控制。该机制的时间窗口随定位长度$ξ$呈指数增长。

英文摘要:

Anderson localization confines the wave function of a quantum particle in a one-dimensional random potential to a volume of the order of the localization length $ξ$. Nonlinear add-ons to the wave dynamics mimic many-body interactions on a mean field level, and result in escape from the Anderson cage and in unlimited subdiffusion of the interacting cloud. We address quantum corrections to that subdiffusion by (i) using the ultrafast unitary Floquet dynamics of discrete-time quantum walks, (ii) an interaction strength ramping to speed up the subdiffusion, and (iii) an action discretization of the nonlinear terms. We observe the saturation of the cloud expansion of $N$ particles to a volume $\sim Nξ$. We predict and observe a universal intermediate logarithmic expansion regime which connects the mean-field diffusion with the final saturation regime and is entirely controlled by particle number $N$. The temporal window of that regime grows exponentially with the localization length $ξ$.

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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