Charge-density-wave stripe state in fractional quantum spin Hall effects

¹ State Key Laboratory of Functional Materials for Informatics and Shanghai Center for Superconductivity, Shanghai Institute of Microsystem and Information Technology and CAS-Shanghai Science Research Center, Chinese Academy of Sciences - Shanghai 200050, China
² Department of Physics and State Key Laboratory of Surface Physics, Fudan University - Shanghai 200433, China
³ Collaborative Innovation Center of Advanced Microstructures - Nanjing 210093, China

^(a) liwei@mail.sim.ac.cn
^(b) yanchen99@fudan.edu.cn

Received: 31 December 2015
Accepted: 19 February 2016

Abstract

By means of finite-size exact diagonalization, we theoretically study the effect of an inter-spin interaction in a fractional quantum spin Hall system, and demonstrate that the charge-density-wave stripe state can be realized in a fractional quantum spin Hall system by tuning the strength of an inter-spin interaction, which clarifies the nature of the puzzling mysterious phase emerging in previous studies. The experimental realization of such exotic quantum state as well as its evolution in optical lattices are also discussed. These results may provide insights into the future studies of fractional topological insulators.