Nagaoka ferromagnetism in moire triangular supperlattice complexes

Abstract

We examine the finite-size twisted TMDs within a moire triangular lattice and analyze their magnetic properties above half-filling. By introducing one electron into a half-filled system, the total spin of the ground state can reach its maximum, leading to the emergence of Nagaoka ferromagnetism. This form of magnetism arises from correlation effects, essentially due to constructive interference among various manybody configurations. We employ exact diagonalization methods to solve the Hubbard Hamiltonian, fully accounting for these correlations. We demonstrate the emergence of Nagaoka ferromagnetism by adding one, two, and three electrons above half-filling, with the ferromagnetic characteristics varying based on the geometries of finite triangular lattices.