Oscillatory pairing of fermions in spin-split traps

TL;DR

This paper investigates how fermions in spin-dependent traps exhibit various pairing phases, including oscillatory pairing, as the trap separation increases, providing a phase diagram relevant for cold-atom experiments.

Contribution

It introduces a detailed phase diagram for fermions in spin-split traps, highlighting the emergence of oscillatory pairing phases in one-dimensional systems.

Findings

Identification of distinct phases: fully paired, oscillatory spin-imbalanced, and fully polarized.

Phase diagram mapping as a function of trap separation.

Predicted experimental signatures for cold-atom systems.

Abstract

As a means of realizing oscillatory pairing between fermions, we study superfluid pairing between two fermion "spin" species that are confined to adjustable spin-dependent trapping potentials. Focusing on the one-dimensional limit, we find that with increasing separation between the spin-dependent traps the fermions exhibit distinct phases, including a fully paired phase, a spin-imbalanced phase with oscillatory pairing, and an unpaired fully spin-polarized phase. We obtain the phase diagram of fermions in such a spin-split trap and discuss signatures of these phases in cold-atom experiments.