Fermi polaron revisited: polaron-molecule transition and coexistence
arXiv:2003.11710 · doi:10.1103/PhysRevA.102.061301
Abstract
We revisit the polaron-molecule transition in three-dimensional(3D) fermion systems using the well-established variational approach. The molecule is found to be intrinsically unstable against lowest-order particle-hole excitations, and it can only approximate the ground state of impurity system with finite total momentum in the strong coupling regime. The polaron-molecule transition can therefore be reinterpreted as a first-order transition between single impurity systems with different total momenta. Within certain interaction window near their transition, both states appear as local minima in the dispersion curve, indicating they can coexist in a realistic system. We have further confirmed the polaron-molecule coexistence in the presence of a finite impurity concentration and at low temperature, which directly leads to a smooth polaron-molecule transition as observed in recent experiments of 3D ultracold Fermi gases. Our results have provided an unambiguous physical picture for the competition and conversion between polaron and molecule, and also shed light on Fermi polaron properties in low dimensions.
arXiv comment5 pages, 5 figures; published version
References in corpus (40)
- Observation of Fermi Polarons in a Tunable Fermi Liquid of Ultracold Atoms
- Metastability and Coherence of Repulsive Polarons in a Strongly Interacting Fermi Mixture
- Attractive and repulsive Fermi polarons in two dimensions
- Universal phase diagram of a strongly interacting Fermi gas with unbalanced spin populations
- The Equation of State of a Low-Temperature Fermi Gas with Tunable Interactions
- Ultrafast many-body interferometry of impurities coupled to a Fermi sea
- Collective Oscillations of an Imbalanced Fermi Gas: Axial Compression Modes and Polaron Effective Mass
- Fermi-Polaron: Diagrammatic Monte Carlo for Divergent Sign-Alternating Series
- Normal state of highly polarized Fermi gases: simple many-body approaches
- Repulsive Fermi polarons in a resonant mixture of ultracold Li atoms
- Normal state of a polarized Fermi gas at unitarity
- Homogeneous Atomic Fermi Gases
- Polaron to molecule transition in a strongly imbalanced Fermi gas
- Normal state of highly polarized Fermi gases: Full many-body treatment
- Two-Dimensional Homogeneous Fermi Gases
- Excitation spectra and rf-response near the polaron-to-molecule transition from the functional renormalization group
- Itinerant ferromagnetism of a repulsive atomic Fermi gas: a quantum Monte Carlo study
- Fermi polarons in two dimensions
- Stability of a Fully Magnetized Ferromagnetic state in Repulsively Interacting Ultracold Fermi Gases
- Repulsive polarons and itinerant ferromagnetism in strongly polarized Fermi gases
- Trimers, molecules and polarons in imbalanced atomic Fermi gases
- Polaron-molecule transitions in a two-dimensional Fermi gas
- Highly polarized Fermi gases in two dimensions
- Analytical theory of the dressed bound state in highly polarized Fermi gases
- Polarons and Molecules in a Two-Dimensional Fermi Gas
- Observation of a smooth polaron-molecule transition in a degenerate Fermi gas
- Decay of polarons and molecules in a strongly polarized Fermi gas
- Attractive Fermi polarons at nonzero temperature with finite impurityconcentration
- Repulsive polarons in two-dimensional Fermi gases
- Highly polarized Fermi gases: One-dimensional case
- Variational approach for impurity dynamics at finite temperature
- An impurity in a Fermi sea on a narrow Feshbach resonance: A variational study of the polaronic and dimeronic branches
- Diagrammatic Monte Carlo study of the Fermi polaron in two dimensions
- Many Fermi polarons at nonzero temperature
- Thermal crossover, transition, and coexistence in Fermi polaronic spectroscopies
- Ab initio lattice results for Fermi polarons in two dimensions
- Diagrammatic Monte Carlo study of quasi-two-dimensional Fermi-polarons
- Polarons and Molecules in a Fermi Gas with Orbital Feshbach Resonance
- A smooth polaron-molecule crossover in a Fermi system
- A Non-Gaussian Variational Approach to Fermi Polarons in One- and Two-dimensional Lattices
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- Non-Hermitian Squeezed Polarons
- Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium
- Thermodynamic signatures of the polaron-molecule transition in a Fermi gas
- Finite-range effects in the unitary Fermi polaron
- Nature of polaron-molecule transition in Fermi polarons
- Emergence of Crystalline Few-body Correlations in Mass-imbalanced Fermi Polarons
- An impurity immersed in a double Fermi Sea
- Competing few-body correlations in ultracold Fermi polarons
- Momentum-dependent quasiparticle properties of the Fermi polaron from the functional renormalization group
- Mass-gap description of heavy impurities in Fermi gases
- Efficient variational approach to the Fermi polaron problem in two dimensions, both in and out of equilibrium
- The normal state of attractive Fermi gases from coupled-cluster theory
- Functional-renormalization-group approach to strongly coupled Bose-Fermi mixtures in two dimensions
- Quench dynamics and quantum flutter properties of one-dimensional attractive single-spin flipped Fermi gases