# Ultrafast Control of Spin Interactions in Honeycomb Antiferromagnetic Insulators

## TL;DR

This paper demonstrates how polarized laser pulses can ultrafastly and nonthermally control exchange and Dzyaloshinskii-Moriya interactions in honeycomb antiferromagnetic insulators, enabling rapid spin manipulation.

## Contribution

It introduces a method to tune spin interactions in 2D honeycomb lattices using Floquet theory, revealing control over their amplitudes, signs, and ratios with laser parameters.

## Key findings

- Laser pulses can modify spin interaction strengths and signs.
- Control over exchange and Dzyaloshinskii-Moriya interactions achieved.
- Renormalizations are independent of laser helicity.

## Abstract

Light enables ultrafast, direct and nonthermal control of the exchange and Dzyaloshinskii-Moriya interactions. We consider two-dimensional honeycomb lattices described by the Kane-Mele-Hubbard model at half filling and in the strongly correlated limit, i.e., the Mott insulator phase of a canted antiferromagnet. Based on Floquet theory, we demonstrate that by changing the amplitude and frequency of polarized laser pulses, one can tune the amplitudes and signs of and even the ratio between the exchange and Dzyaloshinskii-Moriya spin interactions. Furthermore, the renormalizations of the spin interactions are independent of helicity. Our results pave the way for ultrafast optical spin manipulation in recently discovered two-dimensional magnetic materials.