# Optical Selection Rules in Spin-Orbit Coupled Systems on Honeycomb Lattice

## TL;DR

This paper explores how optical selection rules in spin-orbit coupled honeycomb lattice systems depend on symmetry and topological phases, revealing spin-valley selective excitations and abrupt changes at topological transitions.

## Contribution

It demonstrates the dependence of optical selection rules on broken symmetries and topological properties in a minimal model of spin-orbit coupled honeycomb systems.

## Key findings

- Spin-valley selective excitation depends on light handedness.
- Optical selection rules vary with symmetry and topological state.
- Abrupt change in spin-valley selectivity at topological transition.

## Abstract

We investigate the optical properties in a minimal model of spin-orbit coupled systems on honeycomb lattice at half-filling. The absorption of the circularly polarized light in the charge and antiferromagnetic ordered states is particularly studied, and the spin-valley selective excitation depending on the handedness of the light is found. It is shown that the optical selection rules plainly differ with the type of broken symmetries and topological properties of the electronic states. Consequently, the abrupt change of spin-valley selectivity in the optical absorption occurs at the topological transition caused by changing the magnitude of the order parameters.