Transport of dipolar Bose-Einstein condensates in a one-dimensional optical lattice

TL;DR

This paper investigates how magnetic dipolar interactions influence superfluidity in Bose-Einstein condensates within a one-dimensional optical lattice, revealing that dipole alignment affects damping and superfluid behavior depending on flow type.

Contribution

It demonstrates how dipole alignment direction impacts superfluid stability and damping in dipolar Bose-Einstein condensates in optical lattices, depending on oscillatory or continuous flow conditions.

Findings

Perpendicular dipole alignment reduces damping in oscillatory flow.

Parallel dipole alignment preserves superfluidity in continuous flow.

Topological excitations and tunnel barriers explain the observed effects.

Abstract

We show that magnetic dipolar interactions can stabilize superfluidity in atomic gases but the dipole alignment direction required to achieve this varies, depending on whether the flow is oscillatory or continuous. If a condensate is made to oscillate through a lattice, damping of the oscillations can be reduced by aligning the dipoles perpendicular to the direction of motion. However, if a lattice is driven continuously through the condensate, superfluid behavior is best preserved when the dipoles are aligned parallel to the direction of motion. We explain these results in terms of the formation of topological excitations and tunnel barrier heights between lattice sites.