Experimental observation of multiple excitonic optical Rabi oscillations in a semiconductor

Data are presented which show eight excitonic density (Rabi) oscillations in an In0.1Ga0.9As/GaAs multiple quantum well at 5 K. Our time resolved two-color pump-probe experimental technique for observing these oscillations is described. The quantum well sample geometry and linear spectrum are shown along with data characterizing the pump and probe pulses. Experimental data is shown to be in excellent agreement with our theoretical calculation of exciton density versus time, verifying the important affect of the Coulomb interaction between carriers in renormalizing the Rabi frequency. The theoretical calculations include the two-fold degenerate light-hole, heavy-hole, and valence bands in the Hartree-Fock form of the semiconductor Bloch equations, with all variables selected to conform to the experiment.