We theoretically studied the exciton geometric structure in layered semiconducting transition metal dichalcogenides. Based on a three-orbital tight-binding model for Bloch electrons which incorporates their geometric structures, an effective exciton Hamiltonian is constructed and solved perturbatively to reveal the relation between the exciton and its electron/hole constituent. We show that the electron—hole Coulomb interaction gives rise to a non-trivial inheritance of the exciton geometric structure from Bloch electrons, which manifests as a valley-dependent center-of-mass anomalous Hall velocity of the exciton when two external fields are applied on the electron and hole constituents, respectively. The obtained center-of-mass anomalous velocity is found to exhibit a non-trivial dependence on the fields, as well as the wave function and valley index of the exciton. These findings can serve as a general guide for the field-control of the valley-dependent exciton transport, enabling the design of novel quantum optoelectronic and valleytronic devices.

我们从理论上研究了层状半导体过渡金属二硫属化物中激子的几何结构。基于结合了布洛赫电子几何结构的三轨道紧束缚模型，构建了有效的激子哈密顿量并进行微扰求解，以揭示激子与其电子/空穴成分之间的关​​系。我们表明，电子-空穴库仑相互作用产生了来自布洛赫电子的激子几何结构的非平凡继承，这表现为当施加两个外部场时激子的谷相关质心反常霍尔速度分别关于电子和空穴成分。发现所获得的质心反常速度表现出对场以及激子的波函数和谷指数的重要依赖性。这些发现可以作为谷相关激子输运场控制的一般指南，从而实现新型量子光电和谷电子器件的设计。