Anomalous Transition Magnetic Moments in two-dimensional Dirac Materials

TL;DR

This paper develops a unified theory describing how electron-electron interactions influence the magnetic response of 2D Dirac materials with spin-orbit coupling, predicting anomalous transition moments that depend on interactions.

Contribution

It introduces a comprehensive model for the magnetic response of various 2D Dirac materials, highlighting the role of electron-electron interactions in producing anomalous transition moments.

Findings

Magnetic response strongly depends on electron-electron interactions.

Prediction of interaction-dependent anomalous transition moments.

Potential for high-sensitivity magnetic probes of electron correlations.

Abstract

We show that the magnetic response of atomically thin materials with Dirac spectrum and spin-orbit interactions can exhibit strong dependence on electron-electron interactions. While graphene itself has a very small spin-orbit coupling, various two-dimensional (2D) compounds "beyond graphene" are good candidates to exhibit the strong interplay between spin-orbit and Coulomb interactions. Materials in this class include dichalcogenides (such as MoS$_2$ and WSe$_2$), silicene, germanene, as well as 2D topological insulators described by the Kane-Mele model. We present a unified theory for their in-plane magnetic field response leading to "anomalous", i.e. electron interaction dependent transition moments. Our predictions can be potentially used to construct unique magnetic probes with high sensitivity to electron correlations.