Spontaneous Formations of Dynamical Steady States in Polariton Condensates

Zhen-Xia Niu,Wei Zhang

doi:10.3389/fphy.2021.696278

Zhen-Xia Niu, Wei Zhang

Open Access

https://doi.org/10.3389/fphy.2021.696278

Copy DOI

Abstract

We present a numerical analysis on dynamical steady states of polariton Bose–Einstein condensates (BECs) in an incoherent exciton reservoir driven by a ring-shaped optical pump. The balance between the loss and gain of polariton BEC induces a variety of steady states with different configurations, including approximate Gaussian distribution and topological defects, such as vortex–antivortex pairs, vortices with a winding number, and solitons. Besides, the system becomes unstable under fast decay rates and small pumping ring, where BECs can no longer exist in the long-time limit. We also confirm the soliton is dynamically stable in this system, with a steady polariton current induced by the repulsive polariton–polariton and polariton–exciton interactions.

Highlights

Polariton is a strong light–matter–coupled quasiparticle formed in semiconductor microcavities
We investigate the spontaneous formation of steady states of polariton Bose–Einstein condensates (BECs) described by open-dissipative GPE (ODGPE) under ring-shaped pump and incoherent exciton reservoir
By varying the pump radius and decay rates, we systematically map out the phase diagram via the density and phase distributions of polariton BEC and investigate the features of different phases

Summary

INTRODUCTION

Polariton is a strong light–matter–coupled quasiparticle formed in semiconductor microcavities. The polariton BEC is a dynamical steady state instead of a thermal equilibrium due to the rapid radiative decay of polariton and optical pump maintaining excitons. The aim of this study was to investigate dynamical steady states of polariton BECs in incoherent exciton reservoir driven by a ring-shaped optical pump. Owing to the nonequilibrium nature of polariton BEC, the ring-shaped pump and decay can induce considerable effect on the steady states. The phase diagram of the steady states of polariton BEC by varying pumping and decay rates is depicted. We find that several steady states can form spontaneously inside the pumping ring due to particle current induced by the nonlinear polariton–polariton and polariton–exciton interaction.

THEORETICAL MODEL

PHASE DIAGRAM

DYNAMICAL EVOLUTION

CONCLUSION

DATA AVAILABILITY STATEMENT