Programme

P.90 -- Posters, VCTP-50

Date: Thursday, 7 August 2025

Time: 08:30 - 10:00

Preliminary study of the correlation effects of a twisted bilayer structure of transition metal dichalcogenides

Son Trong Nguyen, Hung T. Dang

Faculty of Materials Science and Engineering, Phenikaa University

Twisted bilayer of transition metal dichalcogenides (tTMD) is a new generation of materials for studying strong correlation effects. Similar to twisted bilayer graphene at certain "magic" angles, the low energy electronic structure of tTMD may exhibit extremely narrow bands (flat bands), allowing for significant many-body effects. However, unlike graphene, tTMD may have such flat bands for a wider range of twisted angle, making it accessible for both experimentalists and theorists for investigation. Together with the easy tuning of the electron occupation via the gate voltage, tTMD is considered as a new kind of quantum simulator for studying strongly correlated systems. In this study, we conduct a preliminary theoretical study of a low-energy topologically-trivial Hubbard model of a twisted bilayer structure of triangular TMDs (such as WS$_2$, WSe$_2$, hBN) using single-site dynamical mean-field theory. We discuss all possible aspects of strong correlation in this model, such as the mass enhancement, the Mott transition and the formation of magnetic order at low temperatures. This study will be the starting point for studying other more complicated structures in the family of tTMDs.

Presenter: Nguyen Trong Son