Three‐Branch Excitonic Polaritons in Direct Band Gap Cubic Semiconductors

Abstract

The transition is studied between a photon and "heavy" and "light" excitons in direct-band gap cubic semiconductors with a fourfold degenerated highest valence band at the center of the Brillouin zone. The transition matrix elements are calculated in the second-order approximation of the perturbation series with respect to a small constant proportional to the difference of the mass of the heavy and light holes. The algebraic equation determining the dispersion of the threebranch polaritone is derived. The spin structure of the wave functions of the corresponding excitons is established.