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arXiv 2406.09797cond-mat.mes-hallhep-lat
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环单元和相带拓扑不变量在通用多带陈绝缘体中的应用

Loop unitary and phase band topological invariant in generic multi-band Chern insulators

School of Physics, Henan Normal University(河南师范大学物理学院);School of Physics and Electronics, Hunan University(湖南大学物理与微电子科学学院)

Xi Wu, Ze Yang, Fuxiang Li

AI总结:

研究多带陈绝缘体中环单元和相带拓扑不变量的通用性,通过相变动力学推导出陈数差值,并提出基于相和投影算符的泛化表达式。

摘要:

过去几年中,拓扑相的淬火动力学已得到研究,动态拓扑不变量以不同方式被公式化。然而大多数这些不变量局限于最小系统,其中哈密顿量通过Gamma矩阵扩展。在这里,我们把双带系统中的动态3 winding-number推广到通用多带陈绝缘体中的一个,并证明其值等于淬火前后哈密顿量的陈数之差。此外,我们得到了一个仅依赖于相及其投影算符的表达式,该表达式由gapless fermions在相带中表示,因此适用于所有多带陈绝缘体的淬火。此外,通过淬火三带模型,在(k, t)空间中获得多折叠费米子,这在双带模型中无法实现。

英文摘要:

Quench dynamics of topological phases have been studied in the past few years and dynamical topological invariants are formulated in different ways. Yet most of these invariants are limited to minimal systems in which Hamiltonians are expanded by Gamma matrices. Here we generalize the dynamical 3-winding-number in two-band systems into the one in generic multi-band Chern insulators and prove that its value is equal to the difference of Chern numbers between post-quench and pre-quench Hamiltonians. Moreover we obtain an expression of this dynamical 3-winding-number represented by gapless fermions in phase bands depending only on the phase and its projectors, so it is generic for the quench of all multi-band Chern insulators. Besides, we obtain a multifold fermion in the phase band in (k, t) space by quenching a three-band model, which cannot happen for two band models.

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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