Polarons and dressed molecules near narrow Feshbach resonances

Abstract

The properties of impurities immersed in a large Fermi sea are naturally described in terms of dressed quasiparticles: attractive and repulsive polarons, and dressed molecules. Motivated by recent experiments on narrow Feshbach resonances, we analyze here how the quasiparticle properties are affected by a non-zero resonance range. We find two interesting analytic results. For large range, the ground state energy close to resonance is shown to become perturbative in the inverse range. In the limit of broad resonance instead, we provide a new Tan's relation linking the impurity ground state energy $E_{\downarrow }$ to the number of atoms in its dressing cloud $\Delta N$. As a corollary, at unitarity one finds $\Delta N=-E_{\downarrow }/{\epsilon }_F$, with ${\epsilon }_F$ the Fermi energy of the bath.

6 pages, 6 figures; minor modifications, published version

References in corpus (21)

• Many-Body Physics with Ultracold Gases
• Theory of ultracold Fermi gases
• Observation of Fermi Polarons in a Tunable Fermi Liquid of Ultracold Atoms
• Generalized Virial Theorem and Pressure Relation for a strongly correlated Fermi gas
• Resonantly-paired fermionic superfluids
• Fermi-Polaron: Diagrammatic Monte Carlo for Divergent Sign-Alternating Series
• Exploring an ultracold Fermi-Fermi mixture: Interspecies Feshbach resonances and scattering properties of 6Li and 40K
• Three-boson problem near a narrow Feshbach resonance
• Number of closed-channel molecules in the BEC-BCS crossover
• Excitation spectra and rf-response near the polaron-to-molecule transition from the functional renormalization group
• Two-dimensional dynamics of expansion of a degenerate Bose gas
• General relations for quantum gases in two and three dimensions. II. Bosons and mixtures
• Repulsive polarons and itinerant ferromagnetism in strongly polarized Fermi gases
• Trimers, molecules and polarons in imbalanced atomic Fermi gases
• Ground state of a tightly bound composite dimer immersed in a Fermi Sea
• Three-dimensional strong localization of matter waves by scattering from atoms in a lattice with a confinement-induced resonance
• Atom-dimer and dimer-dimer scattering in fermionic mixtures near a narrow Feshbach resonance
• Decay of polarons and molecules in a strongly polarized Fermi gas
• An impurity in a Fermi sea on a narrow Feshbach resonance: A variational study of the polaronic and dimeronic branches
• Multi-channel scattering and Feshbach resonances: Effective theory, phenomenology, and many-body effects
• Highly Polarized Fermi Gases across a Narrow Feshbach Resonance

Cited by in corpus (39)

• Polarons, Dressed Molecules, and Itinerant Ferromagnetism in ultracold Fermi gases
• Field-theoretical study of the Bose polaron
• Universal many-body response of heavy impurities coupled to a Fermi sea
• Radio frequency spectroscopy of polarons in ultracold Bose gases
• Decoherence of Impurities in a Fermi Sea of Ultracold Atoms
• Universality of an impurity in a Bose-Einstein condensate
• Quantum dynamics of impurities coupled to a Fermi sea
• Feshbach resonances in potassium Bose-Bose mixtures
• Mediated interactions between Fermi polarons and the role of impurity quantum statistics
• Stability and breakdown of Fermi polarons in a strongly interacting Fermi-Bose mixture
• Itinerant Ferromagnetism in a polarized two-component Fermi gas
• An impurity in a Fermi sea on a narrow Feshbach resonance: A variational study of the polaronic and dimeronic branches
• New type of crossover physics in three-component Fermi gases
• Theory of radio-frequency spectroscopy of impurities in quantum gases
• Bloch oscillations of bosonic lattice polarons
• Ground-state properties of Dipolar Bose polarons
• Tunable Feshbach resonances and their spectral signatures in bilayer semiconductors
• The neutron polaron as a constraint on nuclear density functionals
• New theoretical approaches to Bose polarons
• The p-wave polaron
• Mobile impurity in a Fermi sea from the functional renormalization group analytically continued to real time
• Polarons and Molecules in a Fermi Gas with Orbital Feshbach Resonance
• High-polarization limit of the quasi-two-dimensional Fermi gas
• Lifetime of Feshbach dimers in a Fermi-Fermi mixture of ${}^6$Li and ${}^{40}$K
• Thermodynamic signatures of the polaron-molecule transition in a Fermi gas
• Intersections of ultracold atomic polarons and nuclear clusters: How is a chart of nuclides modified in dilute neutron matter?
• Phase diagrams of Fermi gases in a trap with mass and population imbalances at finite temperature
• Rabi oscillations and magnetization of a mobile spin-1/2 impurity in a Fermi sea
• The self-energy of an impurity in an ideal Fermi gas to second order in the interaction strength
• Highly polarized one-dimensional Fermi gases near a narrow $p-$wave resonance
• Electronic properties and polaronic dynamics of semi-Dirac system within ladder approximation
• Attractive polaron formed in doped nonchiral/chiral parabolic system within ladder approximation
• Attractive polaron in a Dirac system within the ladder approximation
• Impurity with a resonance in the vicinity of the Fermi energy
• Polaronic and dressed molecular states in orbital Feshbach resonances
• Resonance-to-bound transition of ${}^5$He in neutron matter and its analogy with heteronuclear Feshbach molecule
• Fermi polaron in a dissipative bath with spin-orbit coupling
• Composite polaron formed on surface of two-dimensional lattice system in weak coupling regime
• Repulsive Fermi and Bose Polarons in Quantum Gases