Degenerate electron-hole plasma formation via resonant exciton excitation in CuCl

We examine the dynamics of photo-generated carriers under resonant exciton excitation with intense femtosecond pulses in CuCl by time-resolved emissio n measurements and mid-infrared (MIR) pump-probe measurements. We observe a broad plasma emission and a strong MIR reflectivity build-up, characterist ic of free motion of electrons and holes. To investigate the creation and r elaxation dynamics of a plasma, we perform time-correlated emission measure ments with double pulse excitation. as well as time-reserved emission and M IR reflectivity measurements. Time-resolved emission and time-correlated em ission measurements show that the interband recombination processes are sup pressed within initial few picoseconds, while the MIR reflectivity builds u p instantaneously. This implies that the unbound electrons and heres are di rectly created via exciton Mott transition. The finite delay for emission i ndicates the formation of interband polarization.