In this paper we describe a strongly nonlinear process of ultrafast photoexcitation of a biased quantum well. This process is governed by coherent dynamical screening, where the instantaneously polarized photoexcited carriers screen initial bias field. This results in a dynamic modification of the bandstructure of the quantum well, which is totally coherent with the temporal intensity distribution of the excitation laser pulse. We developed a time-resolved theoretical model of coherent dynamical screening, which predicts interesting fundamental consequences, such as nonlinear absorption and ultra-broadband THz emission. The results of our THz and optical experiments are in good agreement with the theoretical model.
|Journal||Physica Status Solidi. C, Current topics in solid state physics|
|Publication status||Published - 2006|