Longitudinal–transversal polariton splitting on a GaAs single quantum well microcavity

•Longitudinal–transversal splitting observed on éxciton-polaritons in a SQW GaAs microcavity.•0.19 meV (HH) and 0.137 meV (LH) longitudinal–transversal splitting on a GaAs SQW microcavity.•L–T mode light polarizations show us spin mixing states.•Condensation sign presents only for the longitudinal mode.

Exciton polariton is a quasi-particle formed in a microcavity, which keeps the exciton and the photon property, e.g. the exciton longitudinal–transversal energy splitting. In this work we observed a splitting as large as 0.19 meV in the polariton emission mode in a GaAs single quantum well microcavity for the heavy hole as well as a 0.137 meV for the light hole excitons. The splitting behavior was analyzed as a function of excitation power and the polarization degree. The results indicate one longitudinal–transversal splitting emission light with mixed spin states and crossed linear polarizations for the longitudinal–transversal modes, and a condensation behavior only for the heavy hole transversal mode.