Reduced quantum anomaly in a quasi-2D Fermi superfluid: The significance of the confinement-induced effective range of interactions

Abstract

A two-dimensional (2D) harmonically trapped interacting Fermi gas is anticipated to exhibit a quantum anomaly and possesses a breathing mode at frequencies different from a classical scale invariant value ${\omega }_B=2{\omega }_{\perp }$, where ${\omega }_{\perp }$ is the trapping frequency. The predicted maximum quantum anomaly ($\sim 10\%$) has not been confirmed in experiments. Here, we theoretically investigate the zero-temperature density equation of state and the breathing mode frequency of an interacting Fermi superfluid at the dimensional crossover from three to two dimensions. We find that the simple model of a 2D Fermi gas with a single $s$-wave scattering length is not adequate to describe the experiments in the 2D limit, as commonly believed. A more complete description of quasi-2D leads to a much weaker quantum anomaly, consistent with the experimental observations. We clarify that the reduced quantum anomaly is due to the significant confinement-induced effective range of interactions, which is overlooked in previous theoretical and experimental studies.

arXiv comment5 pages, 4 figures; resubmitted version; the title is changed to emphasize that the experimentally observed reduced quantum anomaly is due to a large effective range of interactions at the current experimental conditions

References in corpus (45)

• Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas
• Exploring the Thermodynamics of a Universal Fermi Gas
• Universal Thermodynamics of Degenerate Quantum Gases in the Unitarity Limit
• Interatomic collisions in a tightly confined Bose gas
• The Equation of State of a Low-Temperature Fermi Gas with Tunable Interactions
• Collective oscillations of a 1D trapped Bose gas
• Breathing Modes and Hidden Symmetry of Trapped Atoms in 2D
• Trapped Fermi gases
• The unitary gas in an isotropic harmonic trap: symmetry properties and applications
• Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover
• Equation of state of a superfluid Fermi gas in the BCS-BEC crossover
• BCS-BEC crossover in a two-dimensional Fermi gas
• Scale invariance and viscosity of a two-dimensional Fermi gas
• Collective modes and ballistic expansion of a Fermi gas in the BCS-BEC crossover
• Universal thermodynamics of strongly interacting Fermi gases
• Ground-state pressure of quasi-2D Fermi and Bose gases
• Equation of State of Ultracold Fermions in the 2D BEC-BCS Crossover Region
• Fulde-Ferrell-Larkin-Ovchinnikov states in one-dimensional spin-polarized ultracold atomic Fermi gases
• An Example of Quantum Anomaly in the Physics of Ultra-Cold Gases
• Quantum anomaly, universal relations, and breathing mode of a two-dimensional Fermi gas
• Thermodynamics of an attractive 2D Fermi gas
• Exact Numerical Results on the Ground State of Strongly Interacting Fermi Gases in Two Dimensions
• Quantum fluctuations in the BCS-BEC crossover of two-dimensional Fermi gases
• Anomalous breaking of scale invariance in a two-dimensional Fermi gas
• Apparent low-energy scale invariance in two-dimensional Fermi gases
• Quantum anomaly and 2D-3D crossover in strongly interacting Fermi gases
• A self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition
• First and second sound in a strongly interacting Fermi gas
• Mean field thermodynamics of a spin-polarized spherically trapped Fermi gas at unitarity
• Scale breaking and fluid dynamics in a dilute two-dimensional Fermi gas
• Breathing mode of two-dimensional atomic Fermi gases in harmonic traps
• Collective oscillations of a trapped quantum gas in low dimensions
• BCS-BEC Crossover of a Quasi-two-dimensional Fermi Gas: the Significance of Dressed Molecules
• Fermi-to-Bose crossover in a trapped quasi-2D gas of fermionic atoms
• Superfluid density and critical velocity near the fermionic Berezinskii-Kosterlitz-Thouless transition
• Variational theory of two-fluid hydrodynamic modes at unitarity
• Quasi two-dimensional superfluid Fermi gases
• Breakdown of scale invariance in a quasi-two-dimensional Bose gas due to the presence of the third dimension
• Effective low-dimensional Hamiltonian for strongly interacting atoms in a transverse trap
• BCS-BEC crossover in a quasi-two-dimensional Fermi gas
• Visualization of Dimensional Effects in Collective Excitations of Optically Trapped Quasi-Two-Dimensional Bose Gases
• Collective modes of a two-dimensional Fermi gas at finite temperature
• Pressure profiles of nonuniform two-dimensional atomic Fermi gases
• Dimensional crossover in a strongly interacting ultracold atomic Fermi gas
• First and second sound of a unitary Fermi gas in highly oblate harmonic traps

Cited by in corpus (32)

• Observing the emergence of a quantum phase transition -- shell by shell
• Coherent vortex dynamics in a strongly-interacting superfluid on a silicon chip
• Collective excitations of a spherical ultradilute quantum droplet
• Three-body repulsive forces among identical bosons in one dimension
• Ground-state Properties and Bogoliubov Modes of a Harmonically Trapped One-Dimensional Quantum Droplet
• Cooper Triples in Attractive Three-Component Fermions: Implication for Hadron-Quark Crossover
• Quantum fluctuations in a strongly interacting Bardeen-Cooper-Schrieffer polariton condensate at thermal equilibrium
• Anomalous frequency shifts in a one-dimensional trapped Bose gas
• Collective modes of ultracold fermionic alkaline-earth gases with SU(N) symmetry
• Precision Many-Body Study of the Berezinskii-Kosterlitz-Thouless Transition and Temperature-Dependent Properties in the Two-Dimensional Fermi Gas
• Few-body perspective of a quantum anomaly in two-dimensional Fermi gases
• Effective theory for ultracold strongly interacting fermionic atoms in two dimensions
• Theory of strongly paired fermions with arbitrary short-range interactions
• Nonrelativistic Conformal Invariance in Mesoscopic Two-Dimensional Fermi Gases
• Polariton-polariton interaction beyond the Born approximation: A toy model study
• Quantum Dynamics of Cold Atomic Gas with $SU(1,1)$ Symmetry
• Pseudogap regime of a strongly interacting two-dimensional Fermi gas with and without confinement-induced effect range of interactions
• Bose-Einstein condensates in an eightfold symmetric optical lattice
• Role of the confinement-induced effective range on the thermodynamics of a strongly correlated Fermi gas in two dimensions
• Superfluidity and pairing phenomena in ultracold atomic Fermi gases in one-dimensional optical lattices, Part I: Balanced case
• Brueckner $G$-matrix approach to two-dimensional Fermi gases with the finite-range attractive interaction
• Dimensional crossover in ultracold Fermi gases from Functional Renormalisation
• Thermodynamic contacts and breathing mode physics of 1D p-wave Fermi gases in the high temperature limit
• Resonantly interacting $p$-wave Fermi superfluid in two dimensions: Tan's contact and breathing mode
• Nonuniversal Equation of State of a Quasi-2D Bose Gas in Dimensional Crossover
• Hierarchical dimensional crossover of an optically-trapped quantum gas with disorder
• Response functions of hot and dense matter in the Nambu-Jona-Lasino model
• Scale and conformal invariance in rotating interacting few-fermion systems
• Precision thermodynamics of the strongly interacting Fermi gas in two dimensions
• When does a Fermi puddle become a Fermi sea? Emergence of pairing in two-dimensional trapped mesoscopic Fermi gases
• Universal clusters in quasi-two-dimensional ultracold Fermi mixtures
• BCS-BEC crossover in a quasi-two-dimensional Fermi superfluid