Comparing contact and dipolar interaction in a Bose-Einstein condensate

Abstract

We have measured the relative strength ${\epsilon }_{d}d$ of the magnetic dipole-dipole interaction compared to the contact interaction in a chromium Bose-Einstein condensate. We analyze the asymptotic velocities of expansion of a dipolar chromium BEC with different orientations of the atomic magnetic dipole moments. By comparing them with numerical solutions of the hydrodynamic equations for dipolar condensates, we are able to determine ${\epsilon }_{d}d=0.159\pm 0.034$ with high accuracy. Since the absolute strength of the dipole-dipole interaction is known exactly, the relative strength of the dipoledipole interaction can be used to determine the s-wave scattering length $a=5.08\pm 1.06\cdot 10^{-}9m=96\pm 20a0$ of 52Cr. This is fully consistent with our previous measurements on the basis of Feshbach resonances.

References in corpus (5)

• Bose-Einstein condensation of chromium
• Observation of dipole-dipole interaction in a degenerate quantum gas
• Exact hydrodynamics of a trapped dipolar Bose-Einstein condensate
• Expansion dynamics of a dipolar Bose-Einstein condensate
• Production of a chromium Bose-Einstein condensate

Cited by in corpus (10)

• Strong dipolar effects in a quantum ferrofluid
• Anisotropic solitons in dipolar Bose-Einstein Condensates
• All-Optical Production of Chromium Bose-Einstein Condensates
• Vortex solitons in dipolar Bose-Einstein Condensates
• Solitons in Tonks-Girardeau gas with dipolar interactions
• Dipolar Bose-Einstein condensates at Finite temperature
• Spinor dipolar Bose-Einstein condensates; Classical spin approach
• Ground states of spin-3 Bose-Einstein condensates for conserved magnetization
• Collective oscillations of dipolar Bose-Einstein condensates and accurate comparison between contact and dipolar interaction
• Low-energy Effective Theory for One-dimensional Lattice Bosons near Integer Filling