Nonadiabatic simulation to study the photoexcited phase change in Ge 2 Sb 2 Te 5

Abstract

Nonadiabatic quantum molecular dynamics (NAQMD) simulations are performed to understand the fast photoexcited phase change of Ge2Sb2Te5 (GST), which is widely used for data storage. NAQMD approach, which simulates energy transfer from excited electrons to the finite temperature ionic system, shows that GST is fast heated up in few picoseconds toward the melting point. This result is considered to be one of the realistic phase change processes through the liquid phase, and also provides an insight on the non-thermal phase change, which is a promising property to improve the speed of phase change.