Magnetism and emergent symmetry in Moiré Chern bands

by Mr Patrick Wilhelm (University Inndbruck)

Tuesday 21 Feb 2023, 11:00 → 12:00 Europe/Zurich

WHGA/121

In recent years, Moir ́materials have emerged as an extremely viable platform for the investigationof correlated phases in condensed matter systems. From pioneering studies of superconductivityin twisted bilayer graphene to potential for mesoscale Hubbard simulators realized via transitionmetal dichalcogenides, these materials promise an unprecedented way of combining theoreticalideas with actual experiments. This talk will focus on strongly interacting fermions in graphenebased Moir ́e systems realizing topologically non-trivial bands with Chern number two. Usingunbiased exact diagonalization simulations complemented by Hartree-Fock, we will deduce theprevalence of spontaneous symmetry breaking as well as the emergence of degenerate manifoldsof states at half-integer band filling. We analyze the nature and competition of these topologicalspin and charge textures, which provide a natural explanation for recent experimental signatures.