Anomalous Dimers in Quantum Mixtures near Broad Resonances: Pauli Blocking, Fermi Surface Dynamics and Implications

Abstract

We study the energetics and dispersion of anomalous dimers that are induced by the Pauli blocking effect in a quantum Fermi gas of majority atoms near interspecies resonances. Unlike in vacuum, we find that both the sign and magnitude of the dimer masses are tunable via Feshbach resonances. We also investigate the effects of particle-hole fluctuations on the dispersion of dimers and demonstrate that the particle-hole fluctuations near a Fermi surface (with Fermi momentum $\hslash k_F$) generally reduce the effective two-body interactions and the binding energy of dimers. Furthermore, in the limit of light minority atoms the particle-hole fluctuations disfavor the formation of dimers with a total momentum $\hslash k_F$, because near $\hslash k_F$ the modes where the dominating particle-hole fluctuations appear are the softest. Our calculation suggests that near broad interspecies resonances when the minority-majority mass ratio $m_B/m_F$ is smaller than a critical value (estimated to be 0.136), dimers in a finite-momentum channel are energetically favored over dimers in the zero-momentum channel. We apply our theory to quantum gases of ${}^6$Li${}^{40}$K, ${}^6$Li${}^{87}$Rb, ${}^{40}$K${}^{87}$Rb and ${}^6$Li${}^{23}$Na near broad interspecies resonances, and discuss the limitations of our calculations and implications.

arXiv comment15 pages, 10 figures, published version

References in corpus (51)

• Feshbach Resonances in Ultracold Gases
• A High Phase-Space-Density Gas of Polar Molecules
• Color superconductivity in dense quark matter
• Pairing and Phase Separation in a Polarized Fermi Gas
• Fermionic Superfluidity with Imbalanced Spin Populations and the Quantum Phase Transition to the Normal State
• Observation of Fermi Polarons in a Tunable Fermi Liquid of Ultracold Atoms
• Spin-Imbalance in a One-Dimensional Fermi Gas
• Universal phase diagram of a strongly interacting Fermi gas with unbalanced spin populations
• Ultracold heteronuclear molecules in a 3D optical lattice
• BEC-BCS crossover in "magnetized" Feshbach-resonantly paired superfluids
• Fermi-Polaron: Diagrammatic Monte Carlo for Divergent Sign-Alternating Series
• Observation of Heteronuclear Feshbach Resonances in a Bose-Fermi Mixture
• Exploring an ultracold Fermi-Fermi mixture: Interspecies Feshbach resonances and scattering properties of 6Li and 40K
• Influence of Induced Interactions on the Superfluid Transition in Dilute Fermi Gases
• Normal state of highly polarized Fermi gases: simple many-body approaches
• Observation of Feshbach resonances between two different atomic species
• Quantum degenerate two-species Fermi-Fermi mixture coexisting with a Bose-Einstein condensate
• Polaron to molecule transition in a strongly imbalanced Fermi gas
• Phase separation in a polarized Fermi gas at zero temperature
• Ultracold Heteronuclear Fermi-Fermi Molecules
• Tuning of heteronuclear interactions in a quantum-degenerate Fermi-Bose mixture
• Feshbach spectroscopy of a K-Rb atomic mixture
• Superfluid stability in BEC-BCS crossover
• Phase diagram of a cold polarized Fermi gas
• Magnetic control of the interaction in ultracold K-Rb mixtures
• A Unitary Fermi Supersolid: The Larkin-Ovchinnikov Phase
• Trimers, molecules and polarons in imbalanced atomic Fermi gases
• Collisional Stability of 40K Immersed in a Strongly Interacting Fermi Gas of 6Li
• Broad Feshbach resonance in the 6Li-40K mixture
• Ground state of a tightly bound composite dimer immersed in a Fermi Sea
• Analytical theory of the dressed bound state in highly polarized Fermi gases
• Hydrodynamic Expansion of a Strongly Interacting Fermi-Fermi Mixture
• Feshbach resonances in mixtures of ultracold ${}^6$Li and ${}^{87}$Rb gases
• Depletion of the Bose-Einstein condensate in Bose-Fermi mixtures
• Decay of polarons and molecules in a strongly polarized Fermi gas
• Heavy-Light Fermion Mixtures at Unitarity
• Crystalline phase of strongly interacting Fermi mixtures
• Collisional Properties of a Polarized Fermi Gas with Resonant Interactions
• Feshbach resonances in an ultracold ${}^7$Li and ${}^{87}$Rb mixture
• Pairing and condensation in a resonant Bose-Fermi mixture
• Feshbach resonances in ultracold 85Rb-87Rb and 6Li-87Rb mixtures
• Superfluid pairing between fermions with unequal masses
• Bose-Fermi Pair Correlations in Attractively Interacting Bose-Fermi Atomic Mixtures
• Breached Superfluidity via P-Wave Coupling
• Pauli Blocking Effect on Efimov States Near Feshbach Resonance
• Resonance Scattering in Optical Lattices and Molecules: Interband versus Intraband Effects
• Carter-like constants of the motion in Newtonian gravity and electrodynamics
• Feshbach resonances in ultracold ^{6,7}Li + ^{23}Na atomic mixtures
• Fermi-Bose Mixtures Near Broad Interspecies Feshbach Resonances
• Bose-Fermi Mixtures Near an Interspecies Feshbach Resonance: Testing a Non Equilibrium Approach
• Comment on "Fermi-Bose Mixtures near Broad Interspecies Feshbach Resonances"

Cited by in corpus (15)

• Mass imbalance effect in resonant Bose-Fermi mixtures
• Efimov States of Heavy Impurities in a Bose-Einstein Condensate
• Condensed phase of Bose-Fermi mixtures with a pairing interaction
• Efimov three-body states on top of a Fermi sea
• Bose Gases Near Resonance: renormalized interactions in a condensate
• Single-particle spectral functions in the normal phase of a strongly-attractive Bose-Fermi mixture
• Phase diagrams of Fermi gases in a trap with mass and population imbalances at finite temperature
• Bose-Fermi mixtures in the molecular limit
• Single-Particle properties of a strongly-interacting Bose-Fermi mixture with mass and population imbalance
• Second root of dilute Bose-Fermi mixtures
• Spectral flow of trimer states of two heavy impurities and one light condensed boson
• Boson-fermion pairing and condensation in two-dimensional Bose-Fermi mixtures
• Correlations and synchronization in a Bose-Fermi mixture
• Non-equilibrium dynamics and atom-pair coherence in strongly interacting Bose-Fermi mixtures
• Mechanical stability of resonant Bose-Fermi mixtures