Evidence for interlayer coupling and moiréexcitons in twisted WS_(2)/WS_(2)homostructure superlattices  

作　　者：Haihong Zheng Biao Wu Shaofei Li Jun He Keqiu Chen Zongwen Liu Yanping Liu 

机构地区：[1]School of Physics and Electronics,Hunan Key Laboratory for Super-microstructure and Ultrafast Process,Central South University,Changsha 410083,China [2]State Key Laboratory of High-Performance Complex Manufacturing,Central South University,Changsha 410083,China [3]Department of Applied Physics,School of Physics and Electronics,Hunan University,Changsha 410082,China [4]School of Chemical and Biomolecular Engineering,The University of Sydney,NSW 2006,Australia [5]The University of Sydney Nano Institute,The University of Sydney,NSW 2006,Australia [6]Shenzhen Research Institute of Central South University,Shenzhen 518000,China

出　　处：《Nano Research》2023年第2期3429-3434,共6页纳米研究（英文版）

基　　金：the National Natural Science Foundation of China(No.61775241);Hunan Provincial Science Fund for Distinguished Young Scholars(No.2020JJ2059);the Youth Innovation Team(No.2019012)of CSU,Hunan province key research and development project(No.2019GK2233);the Science and Technology Innovation Basic Research Project of Shenzhen(No.JCYJ20190806144418859);support of the High-Performance Complex Manufacturing Key State Lab Project,Central South University(No.ZZYJKT2020-12);Z.W.L.thanks the support from the Australian Research Council(ARC Discovery Project,DP180102976).

摘　　要：The formation of moirésuperlattices in twisted van der Waals(vdW)homostructures provides a versatile platform for designing the electronic band structure of two-dimensional(2D)materials.In graphene and transition metal dichalcogenides(TMDs)moirésystems,twist angle has been shown to be a key parameter for regulating the moirésuperlattice.However,the effect of the modulation of the twist angle on moirépotential and interlayer coupling has not been the subject of experimental investigation.Here,we report the observation of the modulation of moirépotential and intralayer excitons in the WS_(2)/WS_(2)homostructure.By accurately adjusting the torsion angle of the homobilayers,the depth of the moirépotential can be modulated.The confinement effect of the moirépotential on the intralayer excitons was further demonstrated by the changing of temperature and valley polarization.Furthermore,we show that a detection of atomic reconstructions by the low-frequency Raman mapping to map out inhomogeneities in moirélattices on a large scale,which endows the uniformity of interlayer coupling.Our results provide insights for an in-depth understanding of the behaviors of moiréexcitons in the twisted van der Waals homostructure,and promote the study of electrical engineering and topological photonics.

关 键 词：moirésuperlattices moiréexcitons interlayer coupling moirépotential 

分 类 号：O43[机械工程—光学工程]