arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1403.7262cond-mat.mes-hallcond-mat.quant-gasquant-ph
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手征对称驱动体系中的拓扑效应

Topological Effects in Chiral Symmetric Driven Systems

Derek Y. H. Ho, Jiangbin Gong

摘要:

近年来,人们对周期驱动系统的拓扑效应产生了浓厚的兴趣。在这项工作中,我们探讨拓扑效应在两个密切相关的二维驱动系统所描述的Floquet运营商具有手征对称性(CS)。我们的数值和分析结果表明以下几点。首先,CS与最近报道的异常反向传播(ACP)模式的存在有关。具体而言,我们表明,一种特殊形式的CS保护ACP模式发生在准能量的$\pm π$。我们还发现,这些模式只存在于沿选定的边界,这表明它们是一个弱的拓扑效应。其次,我们发现CS可以产生受保护的$0$和$π$准能模,并且这些模的数量可以随着我们调整某些系统参数而无限制地增加。与ACP模式一样,这些$0$和$π$模式也仅沿选定边界出现,因此似乎是弱拓扑效应。据我们所知,这项工作是第一次详细研究弱拓扑效应的周期性驱动系统。我们的研究结果增加了驱动拓扑系统的知识。

英文摘要:

Recent years have seen a strong interest in topological effects within periodically driven systems. In this work, we explore topological effects in two closely related 2-dimensional driven systems described by Floquet operators possessing chiral symmetry (CS). Our numerical and analytical results suggest the following. Firstly, the CS is associated with the existence of the anomalous counter-propagating (ACP) modes reported recently. Specifically, we show that a particular form of CS protects the ACP modes occurring at quasienergies of $\pm π$. We also find that these modes are only present along selected boundaries, suggesting that they are a weak topological effect. Secondly, we find that CS can give rise to protected $0$ and $π$ quasienergy modes, and that the number of these modes may increase without bound as we tune up certain system parameters. Like the ACP modes, these $0$ and $π$ modes also appear only along selected boundaries and thus appear to be a weak topological effect. To our knowledge, this work represents the first detailed study of weak topological effects in periodically driven systems. Our findings add to the still-growing knowledge on driven topological systems.

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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