[2112.09232] Effects of quantum fluctuations on low-energy collective modes of a two-dimensional superfluid Fermi gas from the BCS to the Bose limit

Download the PDF of the paper by Senne Van Loon and one other author entitled Effect of Quantum Fluctuations on Low-Energy Collective Modes of a Two-Dimensional Superfluid Fermi Gas

Download PDF

overview: We study the effects of quantum fluctuations on low-energy collective modes in two-dimensional (2D) Fermi superfluids from the BCS to the Bose limit. Comparing the results with recent Bragg scattering experiments on the 2D box potential, the agreement is very good. We show that quantum fluctuations in phase and elastic modulus of pairing order parameters are absolutely necessary to give physically acceptable chemical potential and dispersion relations for low-energy collective modes from BCS to Bose evolution. Furthermore, we show that when the interaction is tuned from the BCS to the Bose regime, the collective mode dispersion changes from concave to convex, never crossing the two-particle continuum. This is because any small attractive interaction produces a bound state in 2D.