Measurements of low-energy excitations in Fermi gases published in Nature Physics

In a recent series of experiments in the ultracold Fermi gas laboratory, CQOS researchers have used Bragg spectroscopy to map out the low-lying excitations in strongly interacting Fermi superfluids. The Bragg spectra are dominated by the Goldstone mode - a gapless collective excitation, or sound wave, that arises due to long-wavelength variations in the phase of the order parameter. In collaboration with theorists from Denmark and Finland, these results further our understandings of sound propagation and pairing in Fermi superfluids.

Link to paper: http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys4187.html