Effective p-wave interaction and topological superfluids in s-wave quantum gases

TL;DR

This paper proposes a simple scheme to create effective p-wave interactions in s-wave quantum gases by using spin-dependent optical lattices, enabling the realization of topological superfluids supporting Majorana fermions without complex setups.

Contribution

It introduces a novel method to synthesize p-wave interactions in s-wave gases using spin-dependent lattices, avoiding the need for spin-orbit coupling or higher orbital loading.

Findings

The system can be mapped to a model of spinless fermions with p-wave interactions.

The ground state can be a topological superfluid supporting Majorana fermions.

The scheme simplifies experimental realization of p-wave superfluids.

Abstract

P-wave interaction in cold atoms may give rise to exotic topological superfluids. However, the realization of p-wave interaction in cold atom system is experimentally challenging. Here we propose a simple scheme to synthesize effective $p$-wave interaction in conventional $s$-wave interacting quantum gases. The key idea is to load atoms into spin-dependent optical lattice potential. Using two concrete examples involving spin-1/2 fermions, we show how the original system can be mapped into a model describing spinless fermions with nearest neighbor p-wave interaction, whose ground state can be a topological superfluid that supports Majorana fermions under proper conditions. Our proposal has the advantage that it does not require spin-orbit coupling or loading atoms onto higher orbitals, which is the key in earlier proposals to synthesize effective $p$-wave interaction in $s$-wave quantum gases, and may provide a completely new route for realizing $p$-wave topological superfluids.