文献类型：期刊文献

英文题名：Emergent fractional quantum anomalous Hall effect in a second-order topological insulator

作者：Zhao, Hongyan[1,2];Xu, Wei[1,2];Xue, Yang[3];Li, Wei[1,2];Yang, Zhongqin[1,2,4]

机构：[1]Fudan Univ, State Key Lab Surface Phys, Shanghai 200433, Peoples R China;[2]Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China;[3]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China;[4]Shanghai Qi Zhi Inst, Shanghai 200030, Peoples R China

年份：2025

卷号：112

期号：24

起止页码：1

外文期刊名：PHYSICAL REVIEW B

收录：;EI(收录号：20255219790136);WOS:【SCI-EXPANDED(收录号:WOS:001633890500007)】；

基金：Acknowledgments. This work was supported by the National Natural Science Foundation of China under Grants No. 12174059 and No. 12574254. The calculations were performed at the High Performance Computational Center (HPCC) of the Department of Physics at Fudan University.

语种：英文

外文关键词：Dispersions - Electric insulators - Honeycomb structures - Quantum computers - Quantum theory - Topological insulators - Topology

摘要：The fractional quantum anomalous Hall (FQAH) phase, featuring unique fractionally quantized states, has garnered substantial experimental progress in recent years. To unlock its full potential for applications in advanced electronics, integrating the FQAH phase with nontrivial higher-order topological states hosting fractional corner states is highly promising. Here, we establish a theoretical model on a generic sp2 hybridized honeycomb lattice with a second-order topological insulating (SOTI) index that can give rise to the appealing FQAH state. Two topological flat bands carrying opposite nonzero Chern numbers emerge around the Fermi level, separated by an SOTI band gap. Exact-diagonalization calculations reveal that electron correlations drive the topological flat bands into rare FQAH states at fractional fillings of 1/3 and 2/5. These prominent fractional topological states persist across a wide parameter range, demonstrating exceptional resilience to variations in band dispersion and orbital composition. The coexistence of FQAH and SOTI states is anticipated to be realized in a practical silicene nanomesh material from first-principles calculations. Our work provides a different pathway for the fabrication of multifunctional and highly miniaturized topological quantum devices in pursuit of the topological quantum computing.