Andrei Elistratov | Searcharxiv

arXiv2015

Detuning-controlled internal oscillations in an exciton-polariton condensate

We theoretically analyze exciton-photon oscillatory dynamics within a homogenous polariton gas in presence of energy detuning between the cavity and quantum well modes. Whereas pure Rabi oscillations consist of the particle exchange between the photon and excitons states in the polariton system without any oscillations of the phases of the two sub-condensates, we demonstrate that any non-zero detuning results in oscillations of the relative phase of the photon and exciton macroscopic wave functions. Different initial conditions reveal a variety of behaviors of the relative phase between the two condensates, and a crossover from Rabi-like to Josephson-like oscillations is predicted.

cond-mat.mes-hall↗

arXiv2015

Coupled exciton-photon Bose condensate in path integral formalism

We study the behavior of exciton polaritons in an optical microcavity with an embedded semiconductor quantum well. We use two-component exciton-photon approach formulated in terms of path integral formalism. In order to describe spatial distributions of the exciton and photon condensate densities, the two coupled equations of the Gross-Pitaevskii type are derived. For a homogeneous system, we find the noncondensate photon and exciton spectra, calculate the coefficients of transformation from the exciton-photon basis to the lower-upper polariton basis, and obtain the exciton and photon occupation numbers of the lower and upper polariton branches for nonzero temperatures. For an inhomogeneous system, the set of coupled equations of the Bogoliubov-de-Gennes type is derived. The equations govern the spectra and spatial distributions of noncondensate photons and excitons.

cond-mat.quant-gas↗