Inheritance of the exciton geometric structure from Bloch electrons in two-dimensional layered semiconductors  

作　　者：Jianju Tang Songlei Wang Hongyi Yu 

机构地区：[1]Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing&School of Physics and Astronomy,Sun Yat-sen University(Zhuhai Campus),Zhuhai 519082,China [2]State Key Laboratory of Optoelectronic Materials and Technologies,Sun Yat-sen University(Guangzhou Campus),Guangzhou 510275,China

出　　处：《Frontiers of physics》2024年第4期25-35,共11页物理学前沿（英文版）

基　　金：H.Y.acknowledges the support by the National Natural Science Foundation of China(Grant No.12274477);the Department of Science and Technology of Guangdong Province(No.2019QN01X061).

摘　　要：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.

关 键 词：transition metal dichalcogenides EXCITON geometric structure Berry curvature van der Waals stacking 

分 类 号：O47[理学—半导体物理]