Observing the effect of dimensionality on the stability of strongly interacting fermionic superfluids*

We use ultracold Fermi gases as a model system to directly probe the influence of dimensionality on the stability of fermionic superfluids. Using momentum-resolved Bragg spectroscopy, we measure the superfluid gap of of two- and three-dimensional homogeneous Fermi gases over a wide range of interaction strengths. We find that the superfluid gap follows a universal function of the chemical potential, irrespective of the dimensionality. Comparing our results with other fermionic superfluids suggests that strong correlations and short coherence lengths are more important for the stability of fermionic superfluids than the dimensionality of the system.