Collective modes and the speed of sound in the Fulde-Ferrell-Larkin-Ovchinnikov state

Journal Article · Sun May 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.053630· OSTI ID:21546843

Heikkinen, M O. J.; Toermae, P ^[1]

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1. Department of Applied Physics, Aalto University School of Science, P.O.Box 15100, FI-00076 Aalto (Finland)

We consider the density response of a spin-imbalanced ultracold Fermi gas in an optical lattice in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. We calculate the collective mode spectrum of the system in the generalized random-phase approximation and find that, although the collective modes are damped even at zero temperature, the damping is weak enough to have well-defined collective modes. We calculate the speed of sound in the gas and show that it is anisotropic due to the anisotropy of the FFLO pairing, which implies an experimental signature for the FFLO state.

• OSTI ID: 21546843
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 83; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR MOMENTUM
ANISOTROPY
APPROXIMATIONS
CALCULATION METHODS
DAMPING
DENSITY
FERMI GAS
LATTICE PARAMETERS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
RANDOM PHASE APPROXIMATION
SOUND WAVES
SPECTRA
SPIN
VELOCITY