English

Comparing contact and dipolar interaction in a Bose-Einstein condensate

Other Condensed Matter 2007-05-23 v1

Abstract

We have measured the relative strength ϵdd\epsilon_dd 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 ϵdd=0.159±0.034\epsilon_dd = 0.159\pm0.034 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±1.06109m=96±20a0a = 5.08\pm1.06\cdot10^-9 m = 96\pm20 a0 of 52Cr. This is fully consistent with our previous measurements on the basis of Feshbach resonances.

Keywords

Cite

@article{arxiv.cond-mat/0608171,
  title  = {Comparing contact and dipolar interaction in a Bose-Einstein condensate},
  author = {Axel Griesmaier and Jürgen Stuhler and Tobias Koch and Marco Fattori and Tilman Pfau and Stefano Giovanazzi},
  journal= {arXiv preprint arXiv:cond-mat/0608171},
  year   = {2007}
}
R2 v1 2026-07-22T11:35:38.769Z