# Laser control of magnonic topological phases in antiferromagnets

## TL;DR

This paper demonstrates how laser fields can be used to control and induce topological magnonic phases in antiferromagnets, enabling manipulation of edge states and thermal effects via polarization.

## Contribution

It introduces a method to control magnon topological phases in antiferromagnets using Floquet theory and laser polarization, revealing tunable edge states and thermal Hall effects.

## Key findings

- Linearly polarized lasers generate helical edge magnon states.
- Circularly polarized lasers induce chiral edge magnon states.
- The direction of magnonic thermal Hall effect is controllable by laser chirality.

## Abstract

We study the laser control of magnon topological phases induced by the Aharonov-Casher effect in insulating antiferromagnets (AFs). Since the laser electric field can be considered as a time-periodic perturbation, we apply the Floquet theory and perform the inverse frequency expansion by focusing on the high frequency region. Using the obtained effective Floquet Hamiltonian, we study nonequilibrium magnon dynamics away from the adiabatic limit and its effect on topological phenomena. We show that a linearly polarized laser can generate helical edge magnon states and induce the magnonic spin Nernst effect, whereas a circularly polarized laser can generate chiral edge magnon states and induce the magnonic thermal Hall effect. In particular, in the latter, we find that the direction of the magnon chiral edge modes and the resulting thermal Hall effect can be controlled by the chirality of the circularly polarized laser through the change from the left-circular to the right-circular polarization. Our results thus provide a handle to control and design magnon topological properties in the insulating AF.