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arXiv · 1506.06176

Spin nematic order in antiferromagnetic spinor condensates

Tilman Zibold·Vincent Corre·Camille Frapolli·Andrea Invernizzi·Jean Dalibard·Fabrice Gerbier
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Abstract

Large spin systems can exhibit unconventional types of magnetic ordering different from the ferromagnetic or Néel-like antiferromagnetic order commonly found in spin 1/2 systems. Spin-nematic phases, for instance, do not break time-reversal invariance and their magnetic order parameter is characterized by a second rank tensor with the symmetry of an ellipsoid. Here we show direct experimental evidence for spin-nematic ordering in a spin-1 Bose-Einstein condensate of sodium atoms with antiferromagnetic interactions. In a mean field description this order is enforced by locking the relative phase between spin components. We reveal this mechanism by studying the spin noise after a spin rotation, which is shown to contain information hidden when looking only at averages. The method should be applicable to high spin systems in order to reveal complex magnetic phases.

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Tilman Zibold, Vincent Corre, Camille Frapolli, Andrea Invernizzi, Jean Dalibard, Fabrice Gerbier. 2016-04-19. Spin nematic order in antiferromagnetic spinor condensates. https://doi.org/10.1103/physreva.93.023614

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