Dephasing in the quasi-two-dimensional exciton-biexciton system

Direct evidence of reduced dynamic scattering in the lower polariton of a semiconductor microcavity

“…The temperature dependence of the linewidth of the bare exciton, as expected from acoustic and optical phonon scattering is also shown ͑solid line͒, weighted by the excitonic content at ␦ϭ1.2 meV. An acoustic phonon coefficient of 2.1 eV/K, and an optical phonon coefficient of 10 meV are used, in agreement with the measured dependence in the bare QW, 12 and a small inhomogeneous broadening of 25 eV, which is realistic for the investigated quantum well, is also included. The measured temperature dependence in the MP and UP is surprisingly quite different from the one expected by phonon scattering ͑even at large negative detuning where the MP and UP tend to the bare HH and LH exciton͒.…”

“…An absorption linewidth of 60 eV at 5 K is found at the 1s heavy-hole exciton, dominated by radiative decay. 12 The exciton-photon coupling in the microcavity structure leads to three polariton resonances, arising from the mixing of the heavy-hole ͑HH͒ exciton, light-hole ͑LH͒ exciton, and cavity modes. Measurements at 11 K of the polariton resonances at different detuning between the cavity mode and the HH exciton can be fitted by a three coupled-oscillator model from which we have inferred a Rabi splitting of 3.6 meV for the HH and 2.2 meV for the LH excitons.…”

Ultranarrow polaritons in a semiconductor microcavity

“…They conclude that the width is limited by the curvature of the thickness of the epitaxial layers across the sample. Bare excitonic resonances of the same width may also be obtained in wide GaAs/Al 0.3 Ga 0.7 As quantum wells at low temperatures, 6 where the influence of quantum-well disorder is negligible and the homogeneous broadening due to phonon scattering is small. Yet, for a wide GaAs quantum well in a MC, the CP linewidths that have been obtained are much broader than expected from the bare linewidths.…”

“…All three lines are well fitted by Lorentzian line having the same width of ␥ϭ190 eV, indicating a dominating homogeneous broadening. Indeed, for the 25 nm quantum well, an inhomogeneous broadening well below 60 eV has been measured, 6 leaving mostly homogeneous broadening mechanisms for the polaritons, e.g., their radiative decay, and exciton dephasing due to phonon scattering and free-carrier scattering. For these measurements a high-resolution spectrometer was used with a resolution of 30 eV.…”

Stimulated Secondary Emission from Semiconductor Microcavities

“…The experiments are made at a temperature of 5 K in a l cavity (bare linewidth of d MC 260 meV) with wedged thickness and a single homogeneously (inhomogeneously) broadened 25 (10) nm GaAs quantum well located at the antinode resulting in ultranarrow polariton linewidths of less than 200 meV [11][12][13]. The experimental configuration is shown in Fig.…”