Vortices in Fermi superfluids are conventionally induced by Abelian gauge fields. Here we demonstrate how a synthetic, non-Abelian gauge field, namely the spin-orbital-angular-momentum (SOAM) coupling, generates vortices in a Fermi superfluid. The mechanism of the vortex formation can be viewed as the angular analogue to that of the spin-orbit-coupling-induced Fulde-Ferrell state under a Fermi surface deformation. Remarkably, the vortex size is comparable with the beam waist of Raman lasers generating the SOAM coupling, which is typically much larger than previously observed vortices in Fermi superfluids. With tunable size and core structure, these giant vortex states would provide unprecedented experimental access to topological defects in Fermi superfluids.
Wei Yi received his PhD in Physics at the Univeristy of Michigan in 2007. He then worked at the Institute for Theoretical Physics, University of Innsbruck, as a postdoctoral researcher, before joining the faculty of Physics at the University of Science and Technology of China in 2010, where he has stayed to this day. Dr. Yi's main research interest includes ultracold atoms, quantum simulation, and strongly correlated systems.