Dark soliton of polariton condensates under nonresonant PT-symmetric pumping

Abstract

A quantum system in complex potentials obeying parity-time (PT ) symmetry could exhibit all real spectra, starting out in non-Hermitian quantum mechanics. The key physics behind a PT-symmetric system consists of the balanced gain and loss of the complex potential. In this work, we plan to include the nonequilibrium nature, i.e. the intrinsic kinds of gain and loss of a system, to a PT-symmetric many-body quantum system, with the emphasis on the combined effects of non-Hermitian due to nonequilibrium nature and PT symmetry in determining the properties of a system. In this end, we investigate the static and dynamical properties of a dark soliton of a polariton Bose-Einstein condensate under the PT-symmetric non-resonant pumping by solving the driven-dissipative GrossPitaevskii equation both analytically and numerically. We derive the equation of motion for the center of mass of the dark solitons center analytically with the help of the Hamiltonian approach. The resulting equation captures how the combination of the open-dissipative character and PT-symmetry affects the properties of dark soliton, i.e. the soliton relaxes by blending with the background at a finite time. Further numerical solutions are in excellent agreement with the analytical results.