2D Gapless Topological Superfluids Generated by Pairing Phases

TL;DR

This paper explores the emergence of a novel gapless topological superfluid phase in a bilayer Rydberg-dressed Fermi gas, revealing unique edge states and finite temperature behaviors through mean-field analysis.

Contribution

It introduces a new gapless topological superfluid phase with spontaneously modulated pairing phases in a bilayer system, expanding understanding of topological superfluidity.

Findings

Identification of a gapless topological superfluid with quantized topological charges.

Discovery of a zero energy flat band at the edges of the system.

Finite temperature phase diagrams showing two critical temperatures.

Abstract

We systematically investigate the ground state phase diagram and the finite temperature phase transitions for a Rydberg-dressed Fermi gas loaded in a bilayer optical lattice. When an effective finite-ranged attraction is induced, our self-consistent mean-field calculation shows that the gapped topological ( $p$-wave) superfluids in each layer are coupled together by the $s$-wave pairing in an intermediate inter-layer distance with a spontaneously modulated phases between these two order parameters. The obtained ground state is a gapless topological superfluid with quantized topological charges characterizing the gapless points, leading to a zero energy flat band at the edges. Finally, we calculate the finite temperature phase diagrams of this two-dimensional gapless superfluid and observe two distinct critical temperatures, demonstrating the fruitful many-body effects on a paired topological superfluids.