Abstract
The Anderson–Bogoliubov branch of collective excitations in a condensed Fermi gas is treated using the effective bosonic action of Gaussian pair fluctuations. The spectra of collective excitations are treated for finite temperature and momentum throughout the BCS–BEC crossover. The obtained spectra explain, both qualitatively and quantitatively, recent experimental results on Goldstone modes in atomic Fermi superfluids.
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Acknowledgements
The present work is supported by the University Research Fund (BOF) of the University of Antwerp and by the Flemish Research Foundation (FWO-Vl), Project No. G.0429.15.N and the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 665501.
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Klimin, S.N., Kurkjian, H. & Tempere, J. Anderson–Bogoliubov Collective Excitations in Superfluid Fermi Gases at Nonzero Temperatures. J Low Temp Phys 196, 102–110 (2019). https://doi.org/10.1007/s10909-019-02160-3
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DOI: https://doi.org/10.1007/s10909-019-02160-3