Magnetic states in a three-dimensional topological Kondo insulator

TL;DR

This paper explores the magnetic phase diagram of a three-dimensional topological Kondo insulator, revealing stable ferromagnetic and surface magnetic states, and analyzing their effects on topological surface states.

Contribution

It introduces a theoretical study of magnetic phases in 3D topological Kondo insulators using real-space dynamical mean field theory, highlighting surface magnetism and its impact on topological states.

Findings

Ferromagnetic states become stable with hole doping.

Surface magnetism appears near half-filling, resembling A-type antiferromagnetism.

Magnetization shifts and deforms surface states, creating arcs in the spectrum.

Abstract

We theoretically study the magnetic phase diagram of a three-dimensional topological Kondo insulator by means of real-space dynamical mean field theory. We find that ferromagnetically ordered states become stable upon hole doping. Besides a wide ferromagnetic phase, we observe surface magnetism close to half-filling, which corresponds to an A-type antiferromagnetic state. We further study the impact of the magnetism on the symmetry protected surface states and find that depending on the surface and the magnetization direction, surface states are still protected by reflection symmetry present in our model. The symmetry protected surface states are shifted away by the magnetization from their original high symmetry momenta in the Brillouin zone. Remarkably, due to the magnetization, the surface states are deformed, resulting in the appearance of arcs in the momentum resolved spectrum.