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arXiv 2409.01741cond-mat.mes-hallcond-mat.mtrl-scicond-mat.str-el
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螺旋磁体ReAg$_2$Cl$_6$中的平Chern能带与关联态

Flat Chern bands and correlated states in spiral magnet ReAg$_2$Cl$_6$

Fudan University(复旦大学);Shanghai Research Center for Quantum Sciences(上海量子科学研究中心);Hefei National Laboratory(合肥国家实验室)

Kejie Bao, Rui Shi, Huan Wang, Jiaxuan Guo, Jing Wang

AI总结:

预测范德华单层ReAg$_2$Cl$_6$在反铁磁基态中由自旋序与自旋-轨道耦合协同产生平Chern能带,可支持分数Chern绝缘体等关联拓扑态,且该机制可电学调控并适用于Re基化合物家族。

摘要:

我们预测范德华单层ReAg$_2$Cl$_6$在其120°反铁磁基态中,于费米能级处拥有孤立的平Chern能带。其平带与非平庸拓扑源于Re $5d$轨道内共面自旋序与强自旋-轨道耦合的协同效应——这是一种不同于摩尔体系的机制。螺旋自旋织构自然地增大了晶胞,在保持可观相互作用强度的同时降低了载流子密度。多体计算表明,分数填充可支持分数Chern绝缘体与电荷密度波态。值得注意的是,该机制对广泛的Re基化合物家族具有普适性,且自旋构型与平带拓扑均可通过电学手段调控。我们的发现确立了Re基共面反铁磁体作为平Chern能带与关联拓扑相的稳健、可调且实验可及的平台,有望在较高温度下实现。

英文摘要:

We predict the van der Waals monolayer ReAg$_2$Cl$_6$ hosts isolated flat Chern bands at the Fermi level in its $120^\circ$ antiferromagnetic ground state. Their flatness and nontrivial topology arise from the cooperative effect of coplanar spin order and strong spin-orbit coupling within Re $5d$ orbitals-a mechanism distinct from moiré systems. The spiral spin texture naturally enlarges the unit cell, reducing carrier densities while preserving sizable interaction scales. Many-body calculations show that fractional fillings can support fractional Chern insulator and charge-density wave states. Remarkably, the mechanism is generic to a broad family of Re-based compounds, with both spin configuration and flat band topology tunable by electrical manipulation. Our findings establish Re-based coplanar antiferromagnets as a robust, tunable, and experimentally accessible platform for flat Chern bands and correlated topological phases potentially at elevated temperatures.

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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