Quasiparticle excitations in Bose-Fermi mixtures

Abstract

We analyze the excitation spectrum of a three-dimensional(3D) Bose-Fermi mixture with tunable resonant interaction parameters and high hyperfine spin multiplets. We focus on a 3-particle vertex describing fermionic and bosonic atoms which can scatter to create fermionic molecules or disassociate. For a single molecular level, in analogy to the single magnetic impurity problem we argue that the low lying excitations of the mean-field theory are described by the Fermi liquid picture with a quasiparticle weight and charge which is justified by a $1/N_{\psi }$ expansion, expected to be exact in the limit of infinite degeneracy (or very high fermionic spin) $N_{\psi }\to \infty$. Our emphasis is placed on the novel conditions for chemical equilibrium and how many-body chemical reactions renormalize the bosonic chemical potential, modifying condensation and superfluid-insulator transitions.

9 pages, 6 eps figures. Version accepted for publication

References in corpus (8)

• Many-Body Physics with Ultracold Gases
• Degenerate Fermi Gases of Ytterbium
• Instabilities in binary mixtures of one-dimensional quantum degenerate gases
• Observation of interspecies Feshbach resonances in an ultracold Rb-Cs mixture
• Strong coupling theory for the superfluidity of Bose-Fermi mixtures
• Superfluid-insulator transition in Fermi-Bose mixtures and the orthogonality catastrophe
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Cited by in corpus (2)

• Detecting Entrainment in Fermi-Bose Mixtures
• Composite pairing and superfluidity in a one-dimensional resonant Bose-Fermi mixture