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A Degenerate Bose-Fermi Mixture of Metastable Atoms

J. M. McNamara·T. Jeltes·A. S. Tychkov·W. Hogervorst·W. Vassen
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Abstract

We report the observation of simultaneous quantum degeneracy in a dilute gaseous Bose-Fermi mixture of metastable atoms. Sympathetic cooling of helium-3 (fermion) by helium-4 (boson), both in the lowest triplet state, allows us to produce ensembles containing more than 10^6 atoms of each isotope at temperatures below 1 micro-Kelvin, and achieve a fermionic degeneracy parameter of T/Tf=0.45. Due to their high internal energy, the detection of individual metastable atoms with sub-nanosecond time resolution is possible, permitting the study of bosonic and fermionic quantum gases with unprecedented precision. This may lead to metastable helium becoming the mainstay of quantum atom optics.

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J. M. McNamara, T. Jeltes, A. S. Tychkov, W. Hogervorst, W. Vassen. 2006-06-25. A Degenerate Bose-Fermi Mixture of Metastable Atoms. https://doi.org/10.1103/physrevlett.97.080404

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