Fast Light-Driven Domain Walls in a Parent Cuprate

Quantum materials exhibit fascinating phenomena when perturbed on short time scales or viewed at small length scales. For example, ultrafast light pulses can induce nonequilibrium behaviors that are thermally inaccessible. In addition, rich mesoscopic heterogeneity often exists in equilibrium, including the presence of domain walls that lie at the interface between different domains. Merging direct spatial imaging with ultrafast time resolution therefore has tremendous potential to reveal intriguing light-induced domain wall dynamics but is often experimentally challenging. In this talk, I will show how ultrafast optical pulses can be harnessed to both image and dynamically manipulate the antiferromagnetic domain walls in a variant of the parent cuprates. In particular, I will highlight our discovery that antiferromagnetic domain walls can be driven to fast speeds by intense circularly polarized laser pulses. These results provide an unprecedented view of domain wall dynamics in quantum materials.