Cooling of a Bose-Einstein Condensate by spin distillation

B. Naylor (1) , E. Maréchal (1) , J. Huckans (2) , O. Gorceix (1) , P. Pedri (1) , L. Vernac (1) , B. Laburthe Tolra (1)

1 LPL - Laboratoire de Physique des Lasers
2 Department of Physics

We propose and experimentally demonstrate a new cooling mechanism leading to purification of a spinor Bose-Einstein Condensate (BEC). Our scheme starts with a BEC polarized in the lowest energy spin state. Spin excited states are thermally populated by lowering the single particle energy gap set by the magnetic field. Then these spin-excited thermal components are filtered out, which leads to an increase of the BEC fraction. We experimentally demonstrate such cooling for a spin 3 52Cr dipolar BEC. Our scheme should be applicable to Na or Rb, with perspective to reach temperatures below 1 nK.

Mots clés: magnetocaloric effect; spin distillation; cooling method; spinor condensate; Bose-Einstein condensate

Domaines: Physique Atomique [physics.atom-ph]; Physique [physics]; Gaz Quantiques [cond-mat.quant-gas]; Physique Quantique [quant-ph]

B. Naylor, E. Maréchal, J. Huckans, O. Gorceix, P. Pedri, et al.. Cooling of a Bose-Einstein Condensate by spin distillation. Physical Review Letters, 2015, 115, pp.243002. ⟨10.1103/PhysRevLett.115.243002⟩. ⟨hal-01153675⟩