Remnant superfluid collective phase oscillations in the normal state of systems with resonant pairing

Abstract

The signature of superfluidity in bosonic systems is a sound wave-like spectrum of the single particle excitations which in the case of strong interactions is roughly temperature independent. In fermionic systems, where fermion pairing arises as a resonance phenomenon between free fermions and paired fermionic states (examples are: the atomic gases of lithium or potassium controlled by a Feshbach resonance, polaronic systems in the intermediary coupling regime, d-wave hole pairing in the strongly correlated Hubbard system), remnants of such superfluid characteristics are expected to be visible in the normal state. The single particle excitations maintain there a sound wave like structure for wave vectors above a certain q_{min}(T) where they practically coincide there with the spectrum of the superfluid phase for T<T_{c}. Upon approaching the transition from above this region in q-space extends down to small momenta, except for a narrow region around q=0 where such modes change into damped free particle

arXiv comment5 pages, 3 figures; to appear in Phys Rev B

References in corpus (20)

• Theory of Bose-Einstein condensation in trapped gases
• Observation of resonance condensation of fermionic atom pairs
• Condensation of Pairs of Fermionic Atoms Near a Feshbach Resonance
• Evidence for Superfluidity in a Resonantly Interacting Fermi Gas
• Vanishing of phase coherence in underdoped Bi_2Sr_2CaCu_2O_8+d
• Resonance superfluidity in a quantum degenerate Fermi gas
• The BCS-BEC Crossover in a Gas of Fermi Atoms with a Feshbach Resonance
• The Excitation Spectrum of a Bose-Einstein Condensate
• Plaquette Boson-Fermion Model of Cuprates
• Superfluidity and collective modes in a uniform gas of Fermi atoms with a Feshbach resonance
• Collective oscillations of a trapped Fermi gas near a Feshbach resonance
• Superfluid transition temperature in a trapped gas of Fermi atoms with a Feshbach resonance
• Evidence of Collective Charge Behavior in the Insulating State of Ultrathin Films of Superconducting Metals
• Non-linear feedback effects in coupled Boson-Fermion systems
• On the pseudogap phase in high-T_c superconductors
• Bogoliubov shadow bands in the normal state of superconducting systems with strong pair fluctuations
• Superconductor-insulator transition driven by local dephasing
• The boson-fermion model: An exact diagonalization study
• From local to macroscopic coherence in systems with composite quasi-particles
• Feshbach resonance described by the boson fermion coupling

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• A negative-U interpretation of the femto-second laser pulse induced crystallographic expansion of a cuprate HTSC material reported recently by Gedik et al
• Evolution with hole doping of the electronic excitation spectrum in the cuprate superconductors
• On the Geodesic Nature of Wegner's Flow
• Ultracold atom superfluidity induced by the Feshbach resonance