Strong dipolar effects in a quantum ferrofluid

Abstract

We report on the realization of a Chromium Bose-Einstein condensate (BEC) with strong dipolar interaction. By using a Feshbach resonance, we reduce the usual isotropic contact interaction, such that the anisotropic magnetic dipole-dipole interaction between 52Cr atoms becomes comparable in strength. This induces a change of the aspect ratio of the cloud, and, for strong dipolar interaction, the inversion of ellipticity during expansion - the usual "smoking gun" evidence for BEC - can even be suppressed. These effects are accounted for by taking into account the dipolar interaction in the superfluid hydrodynamic equations governing the dynamics of the gas, in the same way as classical ferrofluids can be described by including dipolar terms in the classical hydrodynamic equations. Our results are a first step in the exploration of the unique properties of quantum ferrofluids.

Final, published version

References in corpus (3)

• Bose-Einstein condensation of chromium
• Observation of dipole-dipole interaction in a degenerate quantum gas
• Quo vadis, cold molecules? - Editorial review

Cited by in corpus (9)

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• Phase Transition in Space: How Far Does a Symmetry Bend Before It Breaks?
• Rabi switch of condensate wavefunctions in a multicomponent Bose gas
• The low-energy excitation spectrum of one-dimensional dipolar quantum gases