Vortices in exciton-polariton condensates with polarization splitting

TL;DR

This paper investigates how polarization splitting in exciton-polariton microcavities influences vortex behavior, revealing coupling effects, string formation, and observable interference patterns in emitted light.

Contribution

It demonstrates the impact of TE-TM splitting and linear polarization pinning on vortex dynamics and interference fringes in polariton condensates, highlighting novel vortex-string interactions.

Findings

TE-TM splitting couples left and right half-vortices.

Linear polarization pinning creates strings attached to half-vortices.

Interference fringes reveal vortex and string configurations.

Abstract

The presence of polarization splitting of exciton-polariton branches in planar semiconductor microcavities has a pronounced effect on vortices in polariton condensates. We show that the TE-TM splitting leads to the coupling between the left and right half-vortices (vortices in the right and left circular components of the condensate), that otherwise do not interact. We analyze also the effect of linear polarization pinning resulted from a fixed splitting between two perpendicular linear polarizations. In this case, half-vortices acquire strings (solitons) attached to them. The half-vortices with strings can be detected by observing the interference fringes of light emitted from the cavity in two circular polarizations. The string affects the fringes in both polarizations. Namely, the half-vortex is characterized by an asymmetric fork-like dislocation in one circular polarization; the fringes in the other circular polarization are continuous, but they are shifted by crossing the string.