SPICE Workshop on Non-equilibrium Quantum Materials Design, June 27th - 29th 2023
Liuyan Zhao
Surface is present in any finite-size material systems, and its impact on phase transitions can be quite unconventional and interesting. Theory predicted a few decades ago that surface can undergo a phase transition into an ordered state at a higher temperature than bulk does when the interaction strength at the surface exceeds that inside the bulk – named as surface and extraordinary phase transitions for surface and bulk, respectively. Van der Waals (vdW) layered magnets provide a unique platform for potentially realizing such a stringent and rare condition. In this presentation, we use a combination of second order nonlinear optics, transport, and transmission electron microscopy to investigate CrSBr, a vdW layered antiferromagnet. We report our finding of surface and extraordinary phase transitions in CrSBr that are separated by 8K.