Will Melissa, Moessner Roderich, Pollmann Frank
<a href="https://ror.org/02kkvpp62">Technical University of Munich</a>, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany.
<a href="https://ror.org/04xrcta15">Munich Center for Quantum Science and Technology (MCQST)</a>, Schellingstr. 4, 80799 München, Germany.
Phys Rev Lett. 2024 Nov 8;133(19):196301. doi: 10.1103/PhysRevLett.133.196301.
We propose the strongly tilted Bose-Hubbard model as a natural platform to explore Hilbert-space fragmentation (HSF) and fracton dynamics in two dimensions in a setup and regime readily accessible in optical lattice experiments. Using a perturbative ansatz, we find HSF when the model is tuned to the resonant limit of on-site interaction and tilted potential. First, we investigate the quench dynamics of this system and observe numerically that the relaxation dynamics strongly depends on the chosen initial state-one of the key signatures of HSF. Second, we identify fractonic excitations with restricted mobility leading to anomalous transport properties. Specifically, we find excitations that show one-dimensional diffusion (z=1/2) as well as excitations that show subdiffusive behavior in two dimensions (z=3/4). Using a cellular automaton, we analyze their dynamics and compare it to an effective hydrodynamic description.
我们提出强倾斜玻色-哈伯德模型作为一个自然平台，用于在光学晶格实验易于实现的设置和参数范围内，探索二维希尔伯特空间碎片化（HSF）和分数子动力学。通过微扰假设，我们发现当模型调整到在位相互作用和倾斜势的共振极限时会出现HSF。首先，我们研究该系统的猝灭动力学，并通过数值观察到弛豫动力学强烈依赖于所选的初始状态——这是HSF的关键特征之一。其次，我们识别出具有受限迁移率的分数子激发，从而导致反常的输运性质。具体而言，我们发现了表现出一维扩散（z = 1/2）的激发以及在二维中表现出亚扩散行为（z = 3/4）的激发。我们使用元胞自动机分析它们的动力学，并将其与有效的流体动力学描述进行比较。
