After the discovery of topological materials, transition between topological trival and nontrivial structures are receiving tremendous attention, since it cannot be described by classical Fermi liquid theory and hold great potential in the next generation ultrafast and highly efficient information storage devices. Such topological phase transition usually occurs under electrostatic field or hydrostatic (or deviatoric) pressure. Collaborated with Prof. Shunhong Zhang at USTC and Prof. Ju Li at MIT, we predict a new mechanism that a normal insulator could transform into topological (crystalline) insulator under laser pulse illumination. Using SnSe as an exemplary material of group IV-VI compounds, we predict an ultrafast (barrierless kinetics) phase transformation (from well-known thermoelectric Pnma phase to another well-knon topological crystalline insulating Fm-3m phase), according to thermodynamic analysis. A novel fast opto-caloric effect is also predicted.

https://www.nature.com/articles/s41427-019-0188-9