Quantized Floquet Topology with Temporal Noise
Quantized Floquet Topology with Temporal Noise
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具有时间噪声的量化 Floquet 拓扑
DOI：
10.1103/physrevlett.127.270601
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发表时间：
2021
影响因子：
8.6
通讯作者：
Kolodrubetz, Michael H.
中科院分区：
文献类型：
--
作者：
Timms, Christopher I.;Sieberer, Lukas M.;Kolodrubetz, Michael H.
时间周期（Floquet）驱动是一种强大的方法来设计物质的量子相位，包括静态哈密顿系统中不可能的基本非平衡态。一个典型的例子是反常的Floquet绝缘体，它表现出拓扑量子化的手征边缘状态类似于陈省身绝缘体，但服从批量本地化。我们研究了这个拓扑系统的响应依赖于时间的噪声，这打破了拓扑保护Floquet对称性。令人惊讶的是，我们发现，通过部分填充的费米子系统和测量每个周期泵送的电荷给出的量化响应，仍然量化到有限的噪声幅度。我们跟踪这个强大的拓扑结构之间的相互作用扩散和泡利阻塞的边缘状态衰减，我们希望应该是强大的相互作用。我们确定的边界的拓扑相的系统与空间无序数值通过水平统计，并证实我们的结果在极限消失的障碍，通过分析Floquet超算子的方法。这种方法建议一个非厄米特Floquet拓扑相位的系统的状态的解释。我们评论量化的其他拓扑响应的情况下，Floquet对称性和潜在的实验实现。
Time-periodic (Floquet) drive is a powerful method to engineer quantum phases of matter, including fundamentally nonequilibrium states that are impossible in static Hamiltonian systems. One characteristic example is the anomalous Floquet insulator, which exhibits topologically quantized chiral edge states similar to a Chern insulator, yet is amenable to bulk localization. We study the response of this topological system to time-dependent noise, which breaks the topologically protecting Floquet symmetry. Surprisingly, we find that the quantized response, given by partially filling the fermionic system and measuring charge pumped per cycle, remains quantized up to finite noise amplitude. We trace this robust topology to an interplay between diffusion and Pauli blocking of edge state decay, which we expect should be robust against interactions. We determine the boundaries of the topological phase for a system with spatial disorder numerically through level statistics, and corroborate our results in the limit of vanishing disorder through an analytical Floquet superoperator approach. This approach suggests an interpretation of the state of the system as a non-Hermitian Floquet topological phase. We comment on quantization of other topological responses in the absence of Floquet symmetry and potential experimental realizations.