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

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.