摘要
Moirésuperlattices of transition metal dichalcogenide(TMD)heterostructures give rise to rich excitonic phenomena associated with the interlayer twist angle.Theoretical calculations of excitons in such systems are typically based on model moirépotentials that mitigate the computational cost.However,predictive understanding of the electron-hole coupling dominating the excitations is crucial to realize the twist-induced modifications of the optical selection rules.In this work,we use many-body perturbation theory to evaluate the relation between twist angle and exciton properties in TMD heterostructures.We present an approach for unfolding excitonic states from the moiréBrillouin zone onto the separate-layer ones.Applying this method to a large-angle twisted MoS^(2)/MoSe^(2) bilayer,we find that the optical spectrum is dominated by mixed electron–hole transitions with different momenta in the separate monolayers,leading to unexpected hybridization between interlayer and intralayer excitons.Our findings offer a design pathway for exciton layer-localization in TMD heterostructures.
基金
The project has received further funding from the European Research Council(ERC),Grant agreement No.101041159
an Israel Science Foundation Grant No.1208/19.M.J.and H.R.K.gratefully acknowledge the National Supercomputing Mission of the Department of Science and Technology,India,and the Science and Engineering Research Board of the Department of Science and Technology,India,for financial support under Grants No.DST/NSM/R&D_HPC_Applications/2021/23 and No.SB/DF/005/2017,respectively
Computational resources were provided by the Oak Ridge Leadership Computing Facility through the Innovative and Novel Computational Impact on Theory and Experiment(INCITE)program,which is a DOE Office of Science User Facility supported under Contract No.DE-AC05-00OR22725
Supercomputer Education and Research Center at Indian Institute of Science
the ChemFarm cluster at the Weizmann Institute of Science.
