Optical Tunable MoiréExcitons in Twisted Hexagonal GaTe Bilayers  

作　　者：韩锦森 赖康 余晓翔 陈家浩 郭宏礼 戴佳钰 Jinsen Han;Kang Lai;Xiaoxiang Yu;Jiahao Chen;Hongli Guo;Jiayu Dai(Department of Physics,National University of Defense Technology,Changsha 410073,China;Hunan Key Laboratory of Extreme Matter and Applications,National University of Defense Technology,Changsha 410073,China;Department of Physics and Astronomy,California State University,Northridge,CA 91330-8268,USA)

机构地区：[1]Department of Physics,National University of Defense Technology,Changsha 410073,China [2]Hunan Key Laboratory of Extreme Matter and Applications,National University of Defense Technology,Changsha 410073,China [3]Department of Physics and Astronomy,California State University,Northridge,CA 91330-8268,USA

出　　处：《Chinese Physics Letters》2023年第6期86-91,共6页中国物理快报（英文版）

基　　金：the National Key R&D Program of China(Grant No.2017YFA0403200);the National Natural Science Foundation of China(Grant No.U1830206);the Science and Technology Innovation Program of Hunan Province(Grant No.2021RC4026)。

摘　　要：Optical fine-tunable layer-hybridized Moiréexcitons are highly in demand for emerging many-body states in two-dimensional semiconductors.We report naturally confined layer-hybridized bright Moiréexcitons with long lifetimes in twisted hexagonal GaTe bilayers,using ab initio many-body perturbation theory and the Bethe–Salpeter equation.Due to the hybridization of electrons and holes between layers,which enhances the brightness of excitons,the twisted bilayer system becomes attractive for optical applications.We find that in both R and H-type stacking Moirésuperlattices,more than 200 meV lateral quantum confinements occur on exciton energies,which results in two scenarios:(1)The ground state bright excitons XA are found to be trapped at two high-symmetry points,with opposite electric dipoles in the R-stacking Moirésupercell,forming a honeycomb superlattice of nearest-neighbor dipolar attraction.(2)For H-stacking case,the XA is found to be trapped at only one high-symmetry point exhibiting a triangular superlattice.Our results suggest that twisted h-GaTe bilayer is one of the promising systems for optical fine-tunable excitonic devices and provide an ideal platform for realizing strong correlated Bose–Hubbard physics.

关 键 词：equation TWISTED STACKING 

分 类 号：O471[理学—半导体物理]