Realizing one-dimensional topological superfluids with ultracold atomic gases

TL;DR

This paper proposes an experimental setup using ultracold fermionic atoms in an optical superlattice to realize a one-dimensional topological superfluid phase, enabling the study of Majorana fermions in a controlled environment.

Contribution

It introduces a novel method to create a topological superfluid with ultracold atoms, simulating Kitaev's model and allowing exploration of Majorana fermions.

Findings

Topological superfluid phase is achievable with current ultracold atom techniques.

The superfluidity is robust beyond perturbative regimes and in harmonic traps.

Methods for preparing and detecting Majorana edge states are discussed.

Abstract

We propose an experimental implementation of a topological superfluid with ultracold fermionic atoms. An optical superlattice is used to juxtapose a 1D gas of fermionic atoms and a 2D conventional superfluid of condensed Feshbach molecules. The latter acts as a Cooper pair reservoir and effectively induces a superfluid gap in the 1D system. Combined with a spin-dependent optical lattice along the 1D tube and laser-induced atom tunneling, we obtain a topological superfluid phase. In the regime of weak couplings to the molecular fl eld and for a uniform gas the atomic system is equivalent to Kitaev's model of a p-wave superfluid. Using a numerical calculation we show that the topological superfluidity is robust beyond the perturbative limit and in the presence of a harmonic trap. Finally we describe how to investigate some physical properties of the Majorana fermions located at the topological superfluid boundaries. In particular we discuss how to prepare and detect a given Majorana edge state.