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We realize a programmable quantum vortex collider in planar and homogeneous atomic Fermi superfluids with tunable inter-particle interactions. We follow a bottom-up approach reminiscent of other atomic platforms featuring control at the single-particle level, and gain exquisite control of individual 2D vortices to assemble them one by one in arbitrary arrangements. In particular, we use the combination of a high resolution microscope objective and a Digital Micromirror Device to create on-demand vortex configurations and we monitor their evolution across the BEC-BCS regimes of fermionic superfluidity. By engineering collisions within and between vortex–antivortex pairs we distinguish the different relaxation processes of the irrotational vortex energy due to sound emission and due to interactions with normal fluid. For the first time, we directly visualize how the annihilation of vortex dipoles radiates a sound pulse. We progress towards a complete microscopic description of the dissipative dynamics of both single and colliding vortex–antivortex pairs, which is at the heart of the relaxation of non-equilibrium states in bosonic and fermionic superfluids, thereby opening the route to exploring new pathways for quantum turbulence decay, vortex by vortex. W. J. Kwon et al. |
Fermions with tunable interactions... In the lithium lab we produce ultracold Fermi gases of 6Li to explore out-of-equilibrium dynamics and transport phenomena in strongly correlated fermionic matter. Atoms are confined into light-imprinted potential structures, simulating the motion of electrons in solid state devices. Our main goal is the study of two-dimensional strongly correlated phases, such as superfluidity across the BCS-BEC crossover and its robustness to disorder.