Abstract:
The realization of synthetic gauge fields for charge-neutral ultracold atoms has opened new opportunities for creating and investigating topological quantum matters in a clean and easy-to-manipulate environment. One can exploit synthetic gauge potentials to rotate quantum gases and access rich intriguing physical phenomena. Among them, quantized vortices have attracted extensive studies, which also appear in other systems such as helium superfluids, superconductors and neutron stars. We investigate novel phenomena of vortex nucleations in a spinor Bose condensate, which are induced by synthetic azimuthal gauge potentials acting as light-induced effective rotations. We identify the main mechanism of vortex nucleations as the dynamical instability of low-energy excitations. Our experimental data has qualitative agreement with the time-dependent Gross-Pitaevskii equation (GPE) simulations and reveals a novel type of vortex nucleations.