Detection of Rabi oscillations in a two-dimensional electron gas under ultrafast intersubband excitation

We investigate the coherent nonlinear response of a 2D electron gas under ultrafast mid-IR excitation. Laser-induced Rabi oscillations result in population redistribution between resonantly excited subband levels. We calculate temporal redistributions using non-Markovian balance equations, taking into account population relaxation and dephasing of the intersubband polarization. Detection schemes, based on terahertz emission of radiation from non-symmetric quantum wells, as well as a two-colour pump probe method, are discussed for signatures of intersubband Rabi oscillations.