2014/05/06 by T. Boulier, H. Terças, D. D. Solnyshkov +4 · 1 citation
Physics and Astronomy · #cond-mat.other #cond-mat.quant-gas #quant-ph
paper · pdf · doi:10.1038/srep09230
published as Scientific Reports volume 5, 9230 (2015) · 5 pages, 5 figures, submitted to PRL
arxiv created 2014/05/06 · arxiv updated 2020/01/30
We report the formation of a ring-shaped array of vortices after injection of angular momentum in a polariton superfluid. The angular momentum is injected by a ℓ= 8 Laguerre-Gauss beam, whereas the global rotation of the fluid is hindered by a narrow Gaussian beam placed at its center. In the linear regime a spiral interference pattern containing phase defects is visible. In the nonlinear (superfluid) regime, the interference disappears and the vortices nucleate as a consequence of the angular momentum quantization. The radial position of the vortices evolves freely in the region between the two pumps as a function of the density. Hydrodynamic instabilities resulting in the spontaneous nucleation of vortex-antivortex pairs when the system size is sufficiently large confirm that the vortices are not constrained by interference when nonlinearities dominate the system.