Programme

P.63 -- Poster, VCTP-46

Date: Wednesday, 6 October 2021

Time: 08:30 - 10:00

Topological Green function of interacting systems

Tran Thi Thanh Mai, Nguyen Duong Bo, Nguyen Hong Son, Tran Minh Tien

Institute of Physics, Vietnam Academy of Science and Technology, Hanoi, Vietnam

We construct a Green function, which can identify the topological nature of interacting systems. It is equivalent to the single-particle Green function of effective non-interacting particles with the Bloch Hamiltonian given by the inverse of the full Green function of the original interacting particles at zero frequency. The topological nature of the interacting insulators is originated from the coincidence of the poles and the zeros of the diagonal elements of the constructed Green function. The cross of the zeros in the momentum space closely relates to the topological nature of insulators. As a demonstration, using the zero's cross, we identify the topological phases of magnetic insulators, where both the ionic potential and the spin exchange between conduction electrons and magnetic moments are present together with the spin-orbital coupling. The topological phase identification is consistent with the topological invariant of the magnetic insulators. We also found an antiferromagnetic state with topologically breaking of the spin symmetry, where electrons with one spin orientation are in topological insulating state, while electrons with the opposite spin orientation are in topologically trivial one.

Presenter: Tran Thi Thanh Mai