Evidences of nonthermal optically induced insulator-to-metal switching in VO$_{2}$*

Strongly cooperative structural and electronic phase transitions at near room temperature make VO$_{2}$ a promising material for an array of high-speed applications in electronics and photonics. The critical step that limits the ultrafast performance is the structural barrier, which is result of subtle interplay between the Mott and Peierls physics. Using femtosecond electron crystallography, we examine the sequence of events resulted from this interplay and show that the cooperative behavior induced by optically induced charge doping may provide an alternative pathway for efficient ultrafast switching bypassing the high thermodynamic barrier required in the temperature-driven phase transition.