Spontaneous rotating vortex lattices in a pumped decaying condensate

TL;DR

This paper models pumped, decaying quantum condensates using a complex Gross-Pitaevskii equation, revealing that large pumping spots induce spontaneous vortex lattices, breaking rotational symmetry without external rotation.

Contribution

It demonstrates that inhomogeneous pumping can lead to spontaneous vortex lattice formation in quantum condensates, a novel insight into their steady-state behavior.

Findings

Homogeneous pumping leads to unstable symmetric solutions.

Finite pumping spots can restore stability.

Large spots cause spontaneous vortex lattice formation.

Abstract

Injection and decay of particles in an inhomogeneous quantum condensate can significantly change its behaviour. We model trapped, pumped, decaying condensates by a complex Gross-Pitaevskii equation and analyse the density and currents in the steady state. With homogeneous pumping, rotationally symmetric solutions are unstable. Stability may be restored by a finite pumping spot. However if the pumping spot is larger than the Thomas-Fermi cloud radius, then rotationally symmetric solutions are replaced by solutions with spontaneous arrays of vortices. These vortex arrays arise without any rotation of the trap, spontaneously breaking rotational symmetry.