论文标题
过渡金属二分法中的激素不稳定性
Excitonic instability in transition metal dichalcogenides
论文作者
论文摘要
当过渡金属二进制元素化的单层缺乏反转对称性时，它们的低能单粒子光谱可以用倾斜的大型狄拉克汉密尔顿人描述。所谓的Janus材料属于该类别。反转对称性也可以通过施加平面外电场或仅存在基板而折断。在这里，我们探讨了缺乏反转对称性的TMDC单层中激子的特性。我们发现激子结合能可以大于电子带隙，从而使这种材料有望构成难以捉摸的激子绝缘体相。我们还研究了对其光导率的激子贡献，并讨论相关的光学选择规则。
When transition-metal dichalcogenide monolayers lack inversion symmetry, their low-energy single particle spectrum can described by tilted massive Dirac Hamiltonians. The so-called Janus materials fall into that category. Inversion symmetry can also be broken by the application of out-of-plane electric fields, or by the mere presence of a substrate. Here we explore the properties of excitons in TMDC monolayers lacking inversion symmetry. We find that exciton binding energies can be larger than the electronic band gap, making such materials promising candidates to host the elusive exciton insulator phase. We also investigate the excitonic contribution to their optical conductivity and discuss the associated optical selection rules.
