Molecular Control of Floquet Topological Phase in Non-adiabatic Thouless Pumping
Molecular Control of Floquet Topological Phase in Non-adiabatic Thouless Pumping
复制标题
非绝热无缝泵浦中Floquet拓扑相的分子控制
DOI：
10.1021/acs.jpclett.3c01746
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Kanai, Yosuke
中科院分区：
文献类型：
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作者：
Zhou, Ruiyi;Kanai, Yosuke
在拓扑Floquet工程的框架下，研究了电子的非绝热无Thouless泵浦，重点研究了化学基团的原子变化如何控制Floket拓扑相的出现。我们使用实时含时密度泛函理论研究了反式聚乙炔的分子水平变化对拓扑不变量，即缠绕数的影响程度。特别研究了反式聚乙炔的几种取代反应，考察了它们对电子结构的不同影响，包括介晶效应、诱导效应和电子共轭效应。通过将拓扑抽运表示为局域Wannier函数的输运动力学，采用最大局域Wannier函数将缠绕数与价键描述联系起来。通过进一步利用最小粒子-空穴激发的量子动力学的规范不变性，电子的拓扑抽运也可以表示为成键和反键轨道之间的循环跃迁。在将拓扑不变性与化学概念联系起来后，我们展示了分子水平上对Floquet拓扑相的出现的控制，为直观地设计具有这种奇异拓扑相的分子系统提供了一个令人兴奋的机会。
Non-adiabatic Thouless pumping of electrons is studied in the framework of topological Floquet engineering, particularly with a focus on how atomistic changes to chemical moieties control the emergence of the Floquet topological phase. We employ real-time time-dependent density functional theory to investigate the extent to which the topological invariant, the winding number, is impacted by molecular-level changes totrans-polyacetylene. In particular, several substitutions totrans-polyacetylene are studied to examine different effects on the electronic structure, including the mesomeric effect, inductive effect, and electron conjugation effect. Maximally localized Wannier functions are employed to relate the winding number to the valence bond description by expressing the topological pumping as the transport dynamics of the localized Wannier functions. By further exploiting the gauge invariance of the quantum dynamics in terms of the minimal particle–hole excitations, the topological pumping of electrons can be also represented as a cyclic transition among the bonding and antibonding orbitals. Having connected the topological invariant to the chemical concepts, we demonstrate molecular-level control of the emergence of the Floquet topological phase, presenting an exciting opportunity for the intuitive engineering of molecular systems with such an exotic topological phase.