Pseudogap Effects of Fermi Gases in the Presence of A Strong Effective Magnetic Field

TL;DR

This paper investigates how strong effective magnetic fields influence the normal state of fermionic superfluids, revealing pseudogap effects and vortex precursors that challenge traditional understanding of Bose condensation.

Contribution

It introduces an extension of Gor'kov theory to describe pseudogap phenomena and vortex precursors in fermionic gases under strong magnetic fields.

Findings

Pseudogap effects organize into vortex precursors above Tc.

Distortions of Abrikosov lattice occur in the normal state.

Bose condensation can occur despite effective one-dimensional Landau levels.

Abstract

We address the important question of how to characterize the normal state of fermionic superfluids under the influence of a strong effective magnetic field, implemented through rapid rotation or novel artificial field techniques. We consider the effects of crossing from BCS to BEC and the role of non-condensed pairs, or pseudogap effects. Using a simple extension of Gor'kov theory we demonstrate how these pairs organize above the transition $T_c$ into precursors of a vortex configuration, which are associated with distortions of the ideal Abrikosov lattice. This non-uniform normal state appears to enable "Bose condensation" in a field which is otherwise problematic due to the effective one-dimensionality of Landau level dispersion.