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Title: Realization and Detection of Fulde-Ferrell-Larkin-Ovchinnikov Superfluid Phases in Trapped Atomic Fermion Systems

Abstract

A Comment on the Letter by T. Mizushima, K. Machida, and M. Ichioka, Phys. Rev. Lett. 94, 060404 (2005)

Authors:
 [1]
  1. Physics Department Florida State University Tallahassee, Florida 32306 (United States)
Publication Date:
OSTI Identifier:
20699596
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 95; Journal Issue: 21; Other Information: DOI: 10.1103/PhysRevLett.95.218903; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COOPER PAIRS; DETECTION; FERMIONS; SUPERFLUIDITY; TRAPPING

Citation Formats

Yang, Kun. Realization and Detection of Fulde-Ferrell-Larkin-Ovchinnikov Superfluid Phases in Trapped Atomic Fermion Systems. United States: N. p., 2005. Web. doi:10.1103/PhysRevLett.95.218903.
Yang, Kun. Realization and Detection of Fulde-Ferrell-Larkin-Ovchinnikov Superfluid Phases in Trapped Atomic Fermion Systems. United States. doi:10.1103/PhysRevLett.95.218903.
Yang, Kun. Fri . "Realization and Detection of Fulde-Ferrell-Larkin-Ovchinnikov Superfluid Phases in Trapped Atomic Fermion Systems". United States. doi:10.1103/PhysRevLett.95.218903.
@article{osti_20699596,
title = {Realization and Detection of Fulde-Ferrell-Larkin-Ovchinnikov Superfluid Phases in Trapped Atomic Fermion Systems},
author = {Yang, Kun},
abstractNote = {A Comment on the Letter by T. Mizushima, K. Machida, and M. Ichioka, Phys. Rev. Lett. 94, 060404 (2005)},
doi = {10.1103/PhysRevLett.95.218903},
journal = {Physical Review Letters},
number = 21,
volume = 95,
place = {United States},
year = {Fri Nov 18 00:00:00 EST 2005},
month = {Fri Nov 18 00:00:00 EST 2005}
}
  • We study theoretically two spatially separate quasi-one-dimensional atomic Fermi gases in a double-well trap. By tuning independently their spin polarizations, a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid or a Bardeen-Cooper-Schrieffer (BCS) superfluid may be formed in each well. We seek the possibility of creating a spatially tunable atomic Josephson junction between two superfluids, which is supposed to be realizable via building a weak link at given positions of the double-well barrier. We show that within mean-field theory the maximum Josephson current is proportional to the order parameter in two wells. Thus, the spatial inhomogeneity of the FFLO order parameter in one well maymore » be directly revealed through the current measurement with the position-tunable link. We anticipate that this type of Josephson measurement can provide useful evidence for the existence of exotic FFLO superfluids. Possible experimental realizations of the Josephson measurements in atomic Fermi gases are discussed.« less
  • We study the angular Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, in which the rotation symmetry is spontaneously broken, in population imbalanced fermion gases near the BCS-BEC crossover. We investigate the superfluid gases at low temperatures on the basis of the Bogoliubov-de Gennes equation and examine the stability against thermal fluctuations using the T-matrix approach beyond the local-density approximation. We find that the angular FFLO state is stabilized in the gases confined in the toroidal trap but not in the harmonic trap. The angular FFLO state is stable near the BCS-BEC crossover owing to the formation of pseudogap. Spatial dependences of number density andmore » local population imbalance are shown for an experimental test.« less
  • We study theoretically the collective modes of a two-component Fermi gas with attractive interactions in a quasi-one-dimensional harmonic trap. We focus on an imbalanced gas in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. Using a mean-field theory, we study the response of the ground state to time-dependent potentials. For potentials with short wavelengths, we find dramatic signatures in the large-scale response of the gas which are characteristic of the FFLO phase. This response provides an effective way to detect the FFLO state in experiments.
  • A rotating ultracold S-wave superfluid Fermi gas is studied when the mismatch in chemical potentials {delta}{mu} (and the population imbalance {delta}n) corresponds to the Larkin-Ovchinnikov-Fulde-Ferrell state in the vicinity of the Lifshitz critical point. It is shown that under these conditions the critical angular velocity {omega}{sub c2} in two-dimensional systems is an oscillating function of temperature and {delta}n giving rise to reentrant superfluid phases. The reason for this behavior is the population by Cooper pairs of the Landau levels (n{>=}1) above the lowest one (n=0)
  • We have studied the distinctive features of the Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) instability and phase transitions in two-dimensional (2D) mesoscopic superconductors placed in magnetic field of arbitrary orientation and rotating superfluid Fermi gases with imbalanced state populations. Using a generalized version of the phenomenological Ginzburg-Landau theory we have shown that the FFLO states are strongly modified by the effect of the trapping potential confining the condensate. The phenomenon of the inhomogeneous state formation is determined by the interplay of three length scales: (i) length scale of the FFLO instability; (ii) 2D system size; (iii) length scale associated with the orbital effect causedmore » either by the Fermi condensate rotation or magnetic field component applied perpendicular to the superconducting disk. We have studied this interplay and resulting quantum oscillation effects in both superconducting and superfluid finite-size systems with FFLO instability and described the hallmarks of the FFLO phenomenon in a restricted geometry. The finite size of the system is shown to affect strongly the conditions of the observability of switching between the states with different vorticities.« less