Chiral topological excitons in a Chern band insulator
Chiral topological excitons in a Chern band insulator
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陈带绝缘体中的手性拓扑激子
DOI：
10.1103/physrevb.96.161101
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发表时间：
2017-10-02
影响因子：
3.7
通讯作者：
Shindou, Ryuichi
中科院分区：
文献类型：
--
作者：
Chen, Ke;Shindou, Ryuichi
一类被称为陈氏带绝缘体的半导体被证明具有非零拓扑陈氏整数和手性激子边缘模式的激子带。利用典型的两波段陈氏绝缘子模型，计算了相互关系函数，得到了激子带及其陈氏整数。最低激子带在电子陈氏绝缘体相中获得$\pm 1$和$\pm 2$等陈氏整数。这种非平凡的拓扑结构可以通过激子边缘模式的非局域光电响应和体模引起的相互关联响应的相移实验观察到。我们的研究结果表明，磁掺杂HgTe， InAs/GaSb量子阱和$\text{(Bi,Sb)}_{2} \text{Te}_{3}$薄膜是拓扑激子学平台的有希望的候选者。
A family of semiconductors called as Chern band insulator are shown to host exciton bands with non-zero topological Chern integers and chiral exciton edge modes. Using a prototypical two-band Chern insulator model, we calculate a cross-correlation function to obtain the exciton bands and their Chern integers. The lowest exciton band acquires Chern integers such as $\pm 1$ and $\pm 2$ in electronic Chern insulator phase. The non-trivial topology can be experimentally observed both by non-local optoelectronic response of exciton edge modes and by a phase shift in the cross-correlation response due to the bulk mode. Our result suggests that magnetically doped HgTe, InAs/GaSb quantum wells and $\text{(Bi,Sb)}_{2} \text{Te}_{3}$ thin film are promising candidates for a platform of topological excitonics.