Density dependent coupling of negatively charged excitons with confined photons in a GaAs/AlAs microcavity

The negatively charged exciton (X(-)) is observed to strongly couple with the microcavity (MC)-confined photons in a GaAs quantum well containing a two-dimensional electron gas with 0 n(e) 3 x 10(10) cm(-2). This strong coupling results in the formation of charged polaritons. The coupling strength is found to depend on root n(c), in analogy to two-level atoms in a cavity. A model is suggested to explain this dependence. The analysis of the reflection and photoluminescence spectra shows that X- is strongly admired with the neutral exciton (X) via their coupling with the MC-photons. The linewidth dependence on n(e) indicates that electron-polariton scattering is effective.