Breakdown of universality for unequal-mass Fermi gases with infinite scattering length

Abstract

We treat small trapped unequal-mass two-component Fermi gases at unitarity within a non-perturbative microscopic framework and investigate the system properties as functions of the mass ratio $\kappa$, and the numbers $N_1$ and $N_2$ of heavy and light fermions. While equal-mass Fermi gases with infinitely large interspecies s-wave scattering length $a_s$ are universal, we find that unequal mass Fermi gases are, for sufficiently large $\kappa$ and in the regime where Efimov physics is absent, not universal. In particular, the $(N_1,N_2)=(2,1)$ and $(3,1)$ systems exhibit three-body (3b) and four-body (4b) resonances at $\kappa =12.314(2)$ and $10.4(2)$, respectively, as well as surprisingly large finite-range (FR) effects. These findings have profound implications for ongoing experimental efforts and quantum simulation proposals that utilize unequal-mass atomic Fermi gases.

4 pages, 2 figures

References in corpus (16)

• Many-Body Physics with Ultracold Gases
• Theory of ultracold Fermi gases
• Quantum degenerate two-species Fermi-Fermi mixture coexisting with a Bose-Einstein condensate
• Low-energy three-body dynamics in binary quantum gases
• Energetics and Structural Properties of Trapped Two-Component Fermi Gases
• Polarized Fermi condensates with unequal masses: Tuning the tricritical point
• Spectrum and Dynamics of the BCS-BEC crossover from a few-body perspective
• BEC-BCS Crossover of a Trapped Two-Component Fermi Gas with Unequal Masses
• Heavy-Light Fermion Mixtures at Unitarity
• Resonant pairing between Fermions with unequal masses
• Universal Fermi Gas with Two- and Three-Body Resonances
• Energy spectrum of harmonically trapped two-component Fermi gases: Three- and Four-Particle Problem
• Superfluid pairing between fermions with unequal masses
• Asymmetric Fermi superfluid with different atomic species in a harmonic trap
• Chandrasekhar-Clogston limit and phase separation in Fermi mixtures at Unitarity
• Small mass- and trap-imbalanced two-component Fermi systems

Cited by in corpus (35)

• Efimov Physics: a review
• Few-body physics with ultracold atomic and molecular systems in traps
• Comparing and contrasting nuclei and cold atomic gases
• Four-body Efimov effect
• Five-Body Efimov Effect and Universal Pentamer in Fermionic Mixtures
• Two-flavor mixture of a few fermions of different mass in a one-dimensional harmonic trap
• Universal four-body states in heavy-light mixtures with positive scattering length
• Few strongly interacting ultracold fermions in one-dimensional traps of different shapes
• Trimers in the resonant 2+1 fermionic problem on a narrow Feshbach resonance : Crossover from Efimovian to Hydrogenoid spectrum
• Crossover trimers connecting continuous and discrete scaling regimes
• Thermodynamics of the two-component Fermi gas with unequal masses at unitarity
• Absence of a four-body Efimov effect in the 2 + 2 fermionic problem
• Multimer formation in 1D two-component gases and trimer phase in the asymmetric attractive Hubbard model
• Few-body resonances of unequal-mass systems with infinite interspecies two-body s-wave scattering length
• Non-universal bound states of two identical heavy fermions and one light particle
• Hyperspherical explicitly correlated Gaussian approach for few-body systems with finite angular momentum
• Diffusion in a system of a few distinguishable fermions in a one-dimensional double-well potential
• Atom-dimer scattering length for fermions with different masses: analytical study of limiting cases
• Lattice model parameters for ultracold nonreactive molecules: chaotic scattering and its limitations
• Zero-temperature phase diagram of Yukawa bosons
• A general T-matrix approach applied to two-body and three-body problems in cold atomic gases
• Atom-dimer scattering amplitude for fermionic mixtures with different masses: s-wave and p-wave contributions
• Tetramers of two heavy and two light bosons
• $P$-wave Efimov physics implications at unitarity
• Efimov physics implications at $p$-wave fermionic unitarity
• Stability of resonantly interacting heavy-light Fermi mixtures
• Mass-imbalanced fermionic mixture in a harmonic trap
• Quench dynamics of mass-imbalanced three-body fermionic systems in a spherical trap
• Analytical solutions for two heteronuclear atoms in a ring trap
• Ground-State Magnetization in Mixtures of a Few Ultra-Cold Fermions in One-Dimensional Traps
• Three-body contact for fermions. I. General relations
• Dipole-Mode Spectrum and Hydrodynamic Crossover in a Resonantly Interacting Two-Species Fermion Mixture
• BCS-BEC crossover of the strongly interacting ${}^6$Li-${}^{40}$K mixture
• Energetics of three interacting mass-imbalanced bodies in a three-dimensional spherical harmonic trap
• Effects of Efimov states on quench dynamics in a three-boson trapped system