Time of a semiconductor-metal phase transition induced by an ultrashort light pulse in vanadium dioxide

A relationship is obtained for a time τ of a photoinduced semiconductor-metal phase transition of the Peierls type under exposure to an ultrashort laser pulse. It is demonstrated that (i) the time τ increases as the pulse energy density W decreases, and (ii) the phase transition is initiated when the pulse energy density W exceeds a critical value W _c . The results obtained are compared with the experiment on irradiation of a vanadium dioxide film in a light field.