Light-induced Weyl semiconductor-to-metal transition mediated by Peierls instability

Elemental tellurium is a strongly spin-orbit coupled Peierls-distorted semiconductor whose band structure features topologically protected Weyl nodes. Using time-dependent density functional theory calculations, we show that impulsive optical excitation can be used to transiently control the amplitude of Peierls distortion, realizing mechanism switch between three states: semiconductor, metal and non-Weyl metal. Further, present experimental evidence this inverse-Peierls distortion using time-resolved second harmonic generation measurements. These results provide pathway multifunctional ultrafast devices introduce systems as viable hosts light-induced topological transitions.