Coherent quantum control of excitons at ultracold and high density in Cu2O with phase manipulated pulses

By phase manipulation of a short laser pulse, it is possible to selectively generate ultracold excitons in a two-photon process while quenching the multiphoton excitation of hot electrons and holes. We show how this technique allows us to suppress the heating of n=1 orthoexcitons in Cu(2)O at high density. Using a laser pulse having an energy of a few microJ and duration of 100 fs, we are thus able to produce a cold exciton gas up to a density of 10(15) cm(-3).