Eur. Phys. J. D (2015) 69: 243
https://doi.org/10.1140/epjd/e2015-60401-4

Regular Article

Mahan polaritons and their lifetime due to hole recoil

TQC, Universiteit Antwerpen, Universiteitsplein 1, 2610 Antwerpen, Belgium

^a e-mail: maarten.baeten@uantwerpen.be

Received: 10 July 2015
Received in final form: 16 September 2015
Published online: 3 November 2015

Abstract

We present a theoretical study on polaritons in doped semiconductor microcavities, focussing on a cavity mode that is resonant with the Fermi edge. In agreement with experimental results, the strong light-matter coupling is maintained under very high doping within our ladder diagram approximation. In particular, we find that the polaritons result from the strong admixing of the cavity mode with the Mahan exciton. The upper Mahan polariton, lying in the electron-hole continuum, always remains visible and has a linewidth due to free interband electron-hole creation. The lower Mahan polariton acquires a finite lifetime due to relaxation of the valence band hole if the electron density exceeds a certain critical value. However, if the Rabi splitting exceeds the inverse hole recoil time, the lower polariton lifetime is only limited by the cavity properties.