Suppression of space broadening of exciton polariton beams by Bloch oscillation effects

TL;DR

This paper demonstrates that applying a linear photon potential induces Bloch oscillations in exciton polariton beams, effectively suppressing space broadening caused by disorder and nonlinear interactions, which aids in polariton circuit design.

Contribution

It introduces a method to suppress space broadening of exciton polariton beams using Bloch oscillations induced by linear photon potentials.

Findings

Bloch oscillations can suppress disorder-induced scattering.

Linear photon potentials induce Bloch oscillations in polaritons.

Suppression of space broadening benefits polariton circuit development.

Abstract

We theoretically study the transport of exciton polaritons under different applied photon potentials. The relation between the photon potentials and the thickness of the cavity layer is calculated by the finite element simulation. The theoretical analysis and numerical calculation indicate that the cavity photon potential is proportional to the thickness of the cavity layer with the coefficient being about $1.8$ meV/nm. Further, the periodic and linear photon potentials are considered to control the transport of the exciton polaritons in weak- and strong-field pump situations. In both situations the periodic potential cannot by itself effectively suppress the scatterings of the disorder potentials of the cavity photons and excitons and the nonlinear exciton-exciton interaction. When the linear potential is added to the cavity photons, the polariton transport exhibits the Bloch oscillation behavior. Importantly, the polariton Bloch oscillation can strongly suppress the space broadening due to the disorder potentials and nonlinear exciton-exciton interaction, which is beneficial for designing the polariton circuits.