Charge Excitation Dynamics in Bosonic Fractional Chern Insulators.
Charge Excitation Dynamics in Bosonic Fractional Chern Insulators.
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DOI：
10.1103/physrevlett.121.086401
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发表时间：
2017-10
影响因子：
8.6
通讯作者：
Xiao-yu Dong;A. Grushin;J. Motruk;F. Pollmann
中科院分区：
文献类型：
--
作者：
Xiao-yu Dong;A. Grushin;J. Motruk;F. Pollmann
Harper-Hofstadter模型在超冷原子气体中的实验实现使这些系统中物质的分数态变得触手可及--当半填满最低能带时，预计会出现分数陈绝缘态(FCI)，以实现足够强的相互作用。实验装置自然允许我们探索这种拓扑态的动力学；然而，人们对它的非平衡性质知之甚少。我们利用密度矩阵重整化群模拟，研究了FCI态对空间局域微扰的响应。在确认了位相的静态性质后，我们发现在边缘动力学中可以清楚地看到这种特征，即无间隙特征。我们发现，该模型中的局部边缘微扰的传播与微扰强度无关。这将单粒子模型的行为与反向传播的边缘态进行了对比，例如非相互作用的Harper-Hofstadter模型，其中手性只在弱扰动下才明显。此外，我们的模拟表明，不可避免地存在从第一排位置到整体的密度泄漏，阻止了对动力学的天真的手征Luttinger理论的解释。
The experimental realization of the Harper-Hofstadter model in ultracold atomic gases has placed fractional states of matter in these systems within reach-a fractional Chern insulator state (FCI) is expected to emerge for sufficiently strong interactions when half-filling the lowest band. The experimental setups naturally allow us to probe the dynamics of this topological state; yet little is known about its out-of-equilibrium properties. We explore, using density matrix renormalization group simulations, the response of the FCI state to spatially localized perturbations. After confirming the static properties of the phase we show that the characteristic, gapless features are clearly visible in the edge dynamics. We find that a local edge perturbation in this model propagates chirally independent of the perturbation strength. This contrasts the behavior of single particle models with counterpropagating edge states, such as the noninteracting Harper-Hofstadter model, where the chirality is manifest only for weak perturbations. Additionally, our simulations show that there is inevitable density leakage from the first row of sites into the bulk, preventing a naive chiral Luttinger theory interpretation of the dynamics.