Light-driven domain walls and stochastic switching in antiferromagnets with Kyle Seyler

Driving quantum materials out of equilibrium with ultrafast laser light opens versatile routes to controlling their ordered states. In magnetic materials, optical pulses can launch coherent spin waves, rapidly suppress magnetic order, and modify magnetic interactions and anisotropy. How to harness these effects to control antiferromagnetic domains is a rich area for exploration. In this talk, I will first review the ways light can modify magnetic order and then discuss two different routes to controlling antiferromagnetic domain states with ultrafast light. In an antiferromagnetic cuprate, ultrafast optical pulses generate spin waves that propel domain walls at high velocities with bidirectional control. In a two-dimensional van der Waals antiferromagnet, ultrafast excitation can induce stochastic switching between two Néel states. I will close by discussing how such switching events may serve as a unique probe of how magnetic order forms and offer new routes to controlling it.

Kyle Seyler received his PhD in Physics from the University of Washington in 2018 under the supervision of Xiaodong Xu, after which worked as a postdoctoral scholar for David Hsieh at Caltech. He joined the Wyant College of Optical Sciences at the University of Arizona in 2023, where his group explores how laser light can control 2D quantum materials. He is a recipient of the U.S. Department of Energy Early Career Research Program award and the AFOSR Young Investigator Program award.

This lecture was made possible by the William C. Ferguson Fund.