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arXiv 1608.06302cond-mat.dis-nncond-mat.mes-hallcond-mat.quant-gasquant-ph
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具有两步Floquet驱动的无序Chern绝缘子

Disordered Chern insulator with a two step Floquet drive

Sthitadhi Roy, G. J. Sreejith

摘要:

我们探讨的物理陈绝缘体进行两步Floquet驱动。我们分析得到的相图,并表明,该系统可以表现出不同的拓扑相位特征的存在和手性的边缘模式的Floquet准能谱的两个散装差距,周围$0$和$π$。我们发现系统的相位依赖于驱动的平均值而不依赖于驱动的振幅。表征相位的体积拓扑不变量可以通过将一段时间内的酉演化映射到能量平凡但拓扑非平凡的时间演化来提取。大量的拓扑不变量的存在下,淬火无序的数值研究揭示了新的过渡诱导强无序(i)从不同的拓扑平凡的绝缘体阶段和(ii)从平凡的拓扑安德森绝缘体阶段在中间的无序强度。准能谱的水平统计的仔细分析表明,在这些过渡附近的“悬浮湮灭”机制。

英文摘要:

We explore the physics of a Chern insulator subjected to a two step Floquet drive. We analytically obtain the phase diagram and show that the system can exhibit different topological phases characterized by presence and chirality of edge-modes in the two bulk gaps of the Floquet quasienergy spectrum, around $0$ and $π$. We find that the phase of the system depends on the mean but not on the amplitude of the drive. The bulk topological invariants characterizing the phases can be extracted by mapping the unitary evolution within a time period to an energetically trivial but topologically non-trivial time evolution. An extensive numerical study of the bulk topological invariants in the presence of quenched disorder reveals new transitions induced by strong disorder (i) from the different topological to trivial insulator phases and (ii) from a trivial to a topological Anderson insulator phase at intermediate disorder strengths. Careful analysis of level statistics of the quasienergy spectrum indicates a `levitation-annihilation' mechanism near these transitions.

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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