Dispersion and Damping of Phononic Excitations in Fermi Superfluid Gases in 2D
We calculate the sound velocity and the damping rate of the collective excitations of a 2D fermionic superfluid in a non-perturbative manner.Specifically, we focus on the Anderson−Bogoliubov excitations in the BEC-BCS crossover regime, as these modes have a sound-like dispersion at low momenta.The calculation is performed within the path-inte