(a) Scheme of the bichromatic superlattice potential along <em>z</em> (black line), made of the superposition of two standing waves of wavelength λ (blue line) and 2 λ (red line)

2013-06-24T00:00:00Z (GMT) by Sylvain Nascimbène
<p><strong>Figure 9.</strong> (a) Scheme of the bichromatic superlattice potential along <em>z</em> (black line), made of the superposition of two standing waves of wavelength λ (blue line) and 2 λ (red line). The energy offset δ in the resulting double-well potential can be controlled using a relative offset in position of the two standing waves. (b) Amplitude of the standing wave along <em>z</em> used for generating the <em>y</em> lattice, which vanishes at <em>z<sub>B</sub></em>. (c) Superlattice potential with the Wannier function in plane <em>B</em> centred on <em>z<sub>B</sub></em>.</p> <p><strong>Abstract</strong></p> <p>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 tunnelling, we obtain a topological superfluid phase. In the regime of weak couplings to the molecular field 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.</p>