Quasiparticle spectrum and dynamical stability of an atomic Bose-Einstein condensate coupled to a degenerate Fermi gas

Abstract

The quasiparticle excitations and dynamical stability of an atomic Bose-Einstein condensate coupled to a quantum degenerate Fermi gas of atoms at zero temperature is studied. The Fermi gas is assumed to be either in the normal state or to have undergone a phase transition to a superfluid state by forming Cooper pairs. The quasiparticle excitations of the Bose-Einstein condensate exhibit a dynamical instability due to a resonant exchange of energy and momentum with quasiparticle excitations of the Fermi gas. The stability regime for the bosons depends on whether the Fermi gas is in the normal state or in the superfluid state. We show that the energy gap in the quasiparticle spectrum for the superfluid state stabilizes the low energy energy excitations of the condensate. In the stable regime, we calculate the boson quasiparticle spectrum, which is modified by the fluctuations in the density of the Fermi gas.

12 pages, 3 figures

References in corpus (18)

• A quasi-pure Bose-Einstein condensate immersed in a Fermi sea
• Resonance superfluidity in a quantum degenerate Fermi gas
• Superfluidity of spin-polarized 6Li
• Zero-temperature phase diagram of binary boson-fermion mixtures
• The Superfluid State of Atomic Li6 in a Magnetic Trap
• Phonon exchange in dilute Fermi-Bose mixtures: tailoring the Fermi-Fermi interaction
• BCS Theory for Trapped Ultracold Fermions
• Pauli Blocking of Collisions in a Quantum Degenerate Atomic Fermi Gas
• Evaporative Cooling of a Two-Component Degenerate Fermi Gas
• Cooper Pairing in Ultracold K-40 Using Feshbach Resonances
• Low energy collective excitations in a superfluid trapped Fermi gas
• Degenerate fermion gas heating by hole creation
• Atomic four-wave mixing: fermions versus bosons
• Collective Modes in a Dilute Bose-Fermi Mixture
• Zero sound density oscillations in Fermi-Bose mixtures
• Single-particle excitations and the order parameter for a trapped superfluid Fermi gas
• Detection of the BCS transition of a trapped Fermi Gas
• Driving superfluidity with photoassociation

Cited by in corpus (7)

• Bose-Fermi Mixtures in One Dimension
• Collective excitations in trapped boson-fermion mixtures: from demixing to collapse
• Collisionless and hydrodynamic excitations of trapped boson-fermion mixtures
• Pairing in two-dimensional boson-fermion mixtures
• Peierls instability, periodic Bose-Einstein condensates and density waves in quasi-one-dimensional boson-fermion mixtures of atomic gases
• Density waves in quasi-one-dimensional atomic gas mixture of boson and two-component fermion
• Phase Separation of a Fast Rotating Boson-Fermion Mixture in the Lowest-Landau-Level Regime