ULTRAFAST DYNAMICS OF COULOMB CORRELATION EFFECTS IN NON-EQUILIBRIUM FERMI SEAS

Abstract

By spectrally resolving the transient four-wave mixing (FWM) signal and the differential transmission signal arising from electron-hole pairs optically excited into the continuum of a GaAs/AlGaAs quantum well structure, we directly measure the dynamics of the quantum coherence among such interacting carriers. We observe a dynamic blue-shift of the coherent FWM emission spectrum with respect to the excitation laser pulse. We interpret our results in terms of dynamic Coulomb correlation effects arising in non-equilibrium degenerate electron-hole systems.