How the coupling to the vacuum field of a microcavity changes the nature of a conduction electron in a doped quantum well

Simone de Liberato (1, 2) , Cristiano Ciuti (1)

1 MPQ (UMR_7162) - Laboratoire Matériaux et Phénomènes Quantiques
2 LPA - Laboratoire Pierre Aigrain

Recent absorption and electroluminescence experiments on microcavities embedding quantum wells have shown strong coupling between a cavity photon mode and the transition between two conduction subbands, being the lowest one filled with a dense two-dimensional electron gas. Through a non-perturbative theory, here we show that the nature of an electron in the excited conduction subband can be profoundly modified by the strong interaction with the cavity vacuum field. For wavevectors larger than the Fermi one, the electron spectral function has a non-trivial structure reminiscent of a Fano resonance, resulting from the coupling between the bare electron and the continuum of cavity polariton modes. We show how these electron states can be selectively excited by resonant electron tunneling from a narrow-band injector and their impact on ultrahigh efficiency polariton electroluminescence in the low excitation regime.

Domaines: Physique Quantique [quant-ph]; Electrons fortement corrélés [cond-mat.str-el]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Simone de Liberato, Cristiano Ciuti. How the coupling to the vacuum field of a microcavity changes the nature of a conduction electron in a doped quantum well. 2008. ⟨hal-00259601v1⟩