Theory of lifetime of exciton incoherently created below its resonance frequency by inelastic scattering

Motoaki Bamba, Shuji Wakaiki, Hideki Ichida, Kohji Mizoguchi, DaeGwi Kim, Masaaki Nakayama, Yasuo Kanematsu

Published 2014-11-13Version 1

When an exciton in semiconductor is scattered and its energy is decreased far below the resonance energy of the bare exciton state, it has been considered that an exciton-polariton is created immediately by the scattering process, because there is no exciton level at that energy. However, according to recent time-resolved measurements of P emission originating from inelastic exciton-exciton scattering, it looks rather natural to consider that the exciton-polariton is created in a finite time scale which is restricted by a coherence volume of the exciton after the scattering. In this interpretation, the exciton remains in this time scale far below its resonance energy as a transient state in a series of processes without violating the quantum physics.