Light-driven topological and magnetic phase transitions in thin-layer antiferromagnets*

In this talk, we will discuss our theoretical study of the effect of low-frequency light pulses in resonance with phonons in the topological and magnetically ordered two septuple-layer (2-SL) MnBi2Te4(MBT) and MnSb2Te4(MST). In both materials, Raman phonons can be excited via non-linear interactions with photo-excited infrared phonons using intense laser pulses attainable in current experimental setups. The light-induced transient lattice distortions change the sign of the effective interlayer exchange interaction and magnetic order accompanied by a topological band transition. We will show that moderate anti-site disorder, typically present in MBT and MST samples, can facilitate such an effect.