Programme

O.29 -- Oral, VCTP-51

Date: Tuesday, 4 August 2026

Time: 16:40 - 17:00

Role of van Hove singularity in moiré structures of twisted bilayer transition metal dichalcogenides

Son Trong Nguyen (1), Duy Hoang Nguyen (1), Hung The Dang (1)

(1) Faculty of Materials Science and Engineering, Phenikaa University

Recently, twisted structures of transition metal dichalcogenides have emerged as a novel testbed for strongly correlated systems. The moiré structures generated from the twisting reveal correlated flat bands around the Fermi level. Twist angles, displacement fields are some of the "knobs" that can be used to tune these low-energy flat bands to simulate familiar models, such as the Hubbard model, experimentally. In this theoretical work, we show that the van Hove singularity of the low-energy density of states of the twisted structure can be controlled by these "knobs", enabling the observation of different phenomena such as the ferromagnetism or non-Fermi liquid behaviors. By employing dynamical mean-field theory, we demonstrate these phenomena using the well-known Hubbard model in triangular lattice and investigate several different quantities such as optical conductivity, spin susceptibility, etc. that exhibit signature behaviors of each phenomenon, which can be useful to measure in experiments.

Presenter: Dang The Hung