Quasi-particle Lifetime in a Mixture of Bose and Fermi Superfluids

Abstract

In this letter, to reveal the effect of quasi-particle interactions in a Bose-Fermi superfluid mixture, we consider the lifetime of quasi-particle of Bose superfluid due to its interaction with quasi-particles in Fermi superfluid. We find that this damping rate, i.e. inverse of the lifetime, has quite different threshold behavior at the BCS and the BEC side of the Fermi superfluid. The damping rate is a constant nearby the threshold momentum in the BCS side, while it increases rapidly in the BEC side. This is because in the BCS side the decay processe is restricted by constant density-of-state of fermion quasi-particle nearby Fermi surface, while such a restriction does not exist in the BEC side where the damping process is dominated by bosonic quasi-particles of Fermi superfluid. Our results are related to collective mode experiment in recently realized Bose-Fermi superfluid mixture.

8 pages and 3 figures including supplemental material

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Cited by in corpus (7)

• Two-Element Mixture of Bose and Fermi Superfluids
• Induced interactions in a superfluid Bose-Fermi mixture
• Damping of long wavelength collective modes in spinor Bose-Fermi mixtures
• Vortex Lattices in the Bose-Fermi Superfluid Mixture
• Nonlinear dynamics of coupled superfluids
• Counterflow in a doubly superfluid mixture of Bosons and Fermions
• Elementary excitations in the hybrid Bose-Fermi system induced by circularly polarized light in a two-dimensional gas of charge carriers with different masses