发表机构
Indian Institute of Technology Guwahati; Bilkent University（印度理工学院古瓦哈提分校; 比尔肯特大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
理论证明在d波交替磁体中，电子-声子耦合可调控受阻原子绝缘相与量子自旋霍尔拓扑相，实现拓扑相的可控切换，为声子调谐自旋电子学提供新途径。
AI 中文摘要
我们从理论上证明了在具有零净磁化、承载非相对论自旋劈裂带的$d$波交替磁体（AM）中，通过电子-声子耦合（EPC）能够调控受阻原子绝缘相与一阶拓扑相之间的相互作用。通过将$d_{x^{2}-y^{2}}$波交替磁体嵌入量子自旋霍尔（QSH）绝缘体中，我们展示了超过临界强度的交替磁序将Bernevig-Hughes-Zhang（BHZ）型拓扑绝缘体（TI）的母体QSH态重构为受阻原子绝缘体（OAI），其特征为具有量子化分数角电荷的非平庸体极化，伴随特征性的带隙内边界态，而自旋陈数消失。在引入足够强的EPC后，极化子修饰重新组织了Wannier中心及相关的有效边缘拓扑，从而削弱了交替磁性诱导的OAI相，并恢复了螺旋QSH边缘模。进一步地，EPC最终将系统驱动至平庸绝缘体。通过揭示交替磁体中拓扑不同绝缘相之间的可控切换机制，我们的研究为非传统磁性平台中声子调谐的自旋电子学功能提供了直接途径。
英文摘要
We theoretically demonstrate control over the interplay between obstructed atomic insulating and first-order topological phases via electron-phonon coupling (EPC) in a $d$-wave altermagnet (AM) that hosts nonrelativistic spin-split bands with zero net magnetization. By embedding a $d_{x^{2}-y^{2}}$-wave AM in a quantum spin Hall (QSH) insulator, we show that an altermagnetic order beyond a critical strength reconstructs the parent QSH state of a Bernevig-Hughes-Zhang (BHZ)-type topological insulator (TI) into an obstructed atomic insulator (OAI), characterized by nontrivial bulk polarization with quantized fractional corner charges, accompanied by characteristic in-gap boundary states, while the spin Chern number vanishes. Upon incorporating sufficiently strong EPC, the polaronic dressing reorganizes the Wannier centers and the associated effective edge topology, thereby weakening the altermagnetism-induced OAI phase and restoring the helical QSH edge modes. Further, EPC eventually drives the system into a trivial insulator. By uncovering a controllable switching mechanism between topologically distinct insulating phases in AMs, our study establishes a direct route toward phonon-tuned spintronic functionalities in unconventional magnetic platforms.
CommentsMain text: 5 pages with 5 PDF figures, and Supplemental Material: 8 pages with 2 PDF figures; Comments are welcome
