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arXiv · 1108.2017

Correlations and Pair Formation in a Repulsively Interacting Fermi Gas

Christian Sanner·Edward J. Su·Wujie Huang·Aviv Keshet·Jonathon Gillen·Wolfgang Ketterle
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Abstract

A degenerate Fermi gas is rapidly quenched into the regime of strong effective repulsion near a Feshbach resonance. The spin fluctuations are monitored using speckle imaging and, contrary to several theoretical predictions, the samples remain in the paramagnetic phase for arbitrarily large scattering length. Over a wide range of interaction strengths a rapid decay into bound pairs is observed over times on the order of 10\hbar/E_F, preventing the study of equilibrium phases of strongly repulsive fermions. Our work suggests that a Fermi gas with strong short-range repulsive interactions does not undergo a ferromagnetic phase transition.

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Christian Sanner, Edward J. Su, Wujie Huang, Aviv Keshet, Jonathon Gillen, Wolfgang Ketterle. 2011-08-09. Correlations and Pair Formation in a Repulsively Interacting Fermi Gas. https://doi.org/10.1103/physrevlett.108.240404

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