Vortex microscopic structure in BCS to BEC Fermi superfluids

Abstract

In order to examine how the vortex core changes its structure when approaching BEC from BCS regime in superfluid fermion-atom gasses we make a systematic numerical study for the core structure of a singly quantized vortex, solving numerically the generalized Bogoliubov-de Gennes equation derived from the fermion–boson model. Numerical calculations reveal that the vortex core can be well characterized by two length scales based on the spatial variation of the fermionic gap functions and those scales show distinctive differences between the BCS and BEC regimes.