Superfluid density and critical velocity near the fermionic Berezinskii-Kosterlitz-Thouless transition

Abstract

We theoretically investigate superfluidity in a strongly interacting Fermi gas confined to two dimensions at finite temperature. Using a Gaussian pair fluctuation theory in the superfluid phase, we calculate the superfluid density and determine the critical temperature and chemical potential at the Berezinskii-Kosterlitz-Thouless transition. We propose that the transition can be unambiguously demonstrated in cold-atom experiments by stirring the superfluid Fermi gas using a red detuned laser beam, to identify the characteristic jump in the local Landau critical velocity at the superfluid-normal interface, as the laser beam moves across the cloud.

6 pages, 5 figures

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• Berezinskii-Kosterlitz-Thouless transition in trapped quasi-two-dimensional Fermi gas near a Feshbach resonance
• Pairing effects in the normal phase of a two-dimensional Fermi gas
• Pseudogap and preformed pairs in the imbalanced Fermi gas in two dimensions
• Fermi-to-Bose crossover in a trapped quasi-2D gas of fermionic atoms
• Composite bosons in the 2D BCS-BEC crossover from Gaussian fluctuations
• Superfluidity and relaxation dynamics of a laser-stirred 2D Bose gas
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Cited by in corpus (26)

• Observation of superfluidity in a strongly correlated two-dimensional Fermi gas
• Reduced quantum anomaly in a quasi-2D Fermi superfluid: The significance of the confinement-induced effective range of interactions
• Second sound in 2D Bose gas: from the weakly interacting to the strongly interacting regime
• Universal expansion of vortex clusters in a dissipative two-dimensional superfluid
• Bose-Einstein condensation of alpha clusters and new soft mode in 12C--52Fe 4N nuclei in field theoretical superfluid cluster model
• Collective modes of a two-dimensional Fermi gas at finite temperature
• Precision Many-Body Study of the Berezinskii-Kosterlitz-Thouless Transition and Temperature-Dependent Properties in the Two-Dimensional Fermi Gas
• Effective theory for ultracold strongly interacting fermionic atoms in two dimensions
• Theory of strongly paired fermions with arbitrary short-range interactions
• Breathing mode frequency of a strongly interacting Fermi gas across the 2D-3D dimensional crossover
• Second sound with ultracold atoms: A brief historical account
• Josephson effect with superfluid fermions in the two-dimensional BCS-BEC crossover
• Pseudogap regime of a strongly interacting two-dimensional Fermi gas with and without confinement-induced effect range of interactions
• Mobile impurity probing a two-dimensional superfluid phase transition
• Density correlation functions and the spatial structure of the two-dimensional BEC-BCS crossover
• Role of the confinement-induced effective range on the thermodynamics of a strongly correlated Fermi gas in two dimensions
• Dimensional crossover in ultracold Fermi gases from Functional Renormalisation
• Dimensionality-induced BCS-BEC crossover in layered superconductors
• Quantum fluctuations of a resonantly interacting $p$-wave Fermi superfluid in two dimensions
• Strong pairing in two dimensions: Pseudogaps, domes, and other implications
• Kosterlitz-Thouless transition and vortex-antivortex lattice melting in two-dimensional Fermi gases with $p$- or $d$-wave pairing
• Ground states of atomic Fermi gases in a two-dimensional optical lattice with and without population imbalance
• Goldstone and Higgs Hydrodynamics in the BCS-BEC Crossover
• Pseudogap regime of a two-dimensional uniform Fermi gas
• Superfluid density reduction and spin-imbalanced pairing in a fermionic superfluid due to dynamical boson exchange
• Dynamical BCS theory of a two-dimensional attractive Fermi gas: effective interactions from Quantum Monte Carlo calculations