Dynamics of the Mott Transition in CuCl with Subpicosecond Time Resolution

Abstract

It is well known that a strongly excited semiconductor crystal may become partly metallic, due to the formation in the medium of a dense plasma of free electron-hole pairs. This plasma phase represents the lowest electronically excited state of the crystal, as long as the free carriers density n exceeds a critical value n_c. If n falls below n_c, the excited system reverts to an insulating (excitonic) phase consisting of strongly correlated electron-hole pairs. The complete understanding of this Mott-like transition, particularly its dynamical aspect, is of great interest, both from a fundamental point of view as well as for potential applications, e.g. in fast switching devices.