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TYC Lunctime Seminar: Electronic structure of twisted bilayer materials
23 May @ 12:00 pm – 12:30 pm
Department of Materials, ICL
Abstract: The discovery of correlated and superconducting states in magic-angle twisted bilayer graphene has generated interest in twisted heterostructures composed of other 2D materials. For example, signatures of superconductivity and exotic optical behaviour have been observed recently in twisted bilayers of transition metal dichalcogenides (TMDs). The theoretical and computational study of these materials using first-principles methods, however, remains challenging due to their large Moiré superlattice sizes at small twist angles. In this work, accurate and efficient tight-binding models for predicting and understanding the electronic structure of twisted TMD heterostructures are developed. The first-principles TMD tight-binding model of Fang et al. is extended to twisted and hetero-bilayer structure and additional interlayer interactions between pz and dz2 orbitals are included. Finally, the band structures and effect of twisting in various Moiré heterostructures of TMDs are demonstrated.