Universal Fluctuations of Floquet Topological Invariants at Low Frequencies.
Universal Fluctuations of Floquet Topological Invariants at Low Frequencies.
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DOI：
10.1103/physrevlett.121.036402
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发表时间：
2017-06
影响因子：
8.6
通讯作者：
M. Rodriguez-Vega;B. Seradjeh;B. Seradjeh
中科院分区：
文献类型：
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作者：
M. Rodriguez-Vega;B. Seradjeh;B. Seradjeh
我们研究低频动力学的周期性驱动的一维系统托管Floquet拓扑相位。我们用解析和数值方法证明，在低频极限Ω→0，手征对称驱动系统的拓扑不变量表现出普适的涨落。虽然这个极限中的拓扑不变量在小范围的频率上平均几乎消失，但我们发现它们遵循宽度为1/sqrt[Ω]的普适高斯分布。我们解释这种缩放的基础上的扩散结构的Floquet-Bloch演化运营商在低频率的缠绕数。我们还发现最大准能隙仍然是有限的，并且标度为Ω^{2}。因此，我们认为，绝热极限的Floquet拓扑绝缘体是高度结构化的，普遍的波动持续到非常低的频率。
We study the low-frequency dynamics of periodically driven one-dimensional systems hosting Floquet topological phases. We show, both analytically and numerically, in the low frequency limit Ω→0, the topological invariants of a chirally symmetric driven system exhibit universal fluctuations. While the topological invariants in this limit nearly vanish on average over a small range of frequencies, we find that they follow a universal Gaussian distribution with a width that scales as 1/sqrt[Ω]. We explain this scaling based on a diffusive structure of the winding numbers of the Floquet-Bloch evolution operator at low frequency. We also find that the maximum quasienergy gap remains finite and scales as Ω^{2}. Thus, we argue that the adiabatic limit of a Floquet topological insulator is highly structured, with universal fluctuations persisting down to very low frequencies.