Mean-field vs RPA calculation of the energy of an impurity immersed in a spin 1/2 superfluid
arXiv:2202.03222 · doi:10.1103/PhysRevA.105.033314
Abstract
In this article we calculate the energy of an impurity weakly coupled to a spin 1/2 fermionic superfluid. We show that the divergences resulting from three-body physics can only be cured using a proper description of the excitations of the many-body background. We highlight the crucial role played by interactions between quasiparticles which are overlooked within BCS (Bardeen-Cooper-Schrieffer) mean-field theory of fermionic superfluidity. By contrast, we prove that their addition using the Random Phase Approximation (RPA) allows us to regularize the energy of the impurity. Finally, we show that these beyond mean-field corrections should be observable by the analysis of the frequency shift of the impurity center of mass oscillations in an external confining potential.
References in corpus (34)
- Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas
- Large momentum part of fermions with large scattering length
- Observation of Fermi Polarons in a Tunable Fermi Liquid of Ultracold Atoms
- Fermi polaron-polaritons in charge-tunable atomically thin semiconductors
- Metastability and Coherence of Repulsive Polarons in a Strongly Interacting Fermi Mixture
- Observation of Attractive and Repulsive Polarons in a Bose-Einstein Condensate
- Bose polarons in the strongly interacting regime
- Universal phase diagram of a strongly interacting Fermi gas with unbalanced spin populations
- Polarons, Dressed Molecules, and Itinerant Ferromagnetism in ultracold Fermi gases
- The Equation of State of a Low-Temperature Fermi Gas with Tunable Interactions
- Three-body forces: From cold atoms to nuclei
- Collective Oscillations of an Imbalanced Fermi Gas: Axial Compression Modes and Polaron Effective Mass
- Fermi-Polaron: Diagrammatic Monte Carlo for Divergent Sign-Alternating Series
- A Mixture of Bose and Fermi Superfluids
- Normal state of a polarized Fermi gas at unitarity
- Bose polarons near quantum criticality
- Impurity in a Bose-Einstein condensate and the Efimov effect
- Collective mode of homogeneous superfluid Fermi gases in the BEC-BCS crossover
- Auxiliary Field quantum Monte Carlo for Strongly Paired Fermions
- Boiling a Unitary Fermi Liquid
- Thermodynamic Measurements in a Strongly Interacting Fermi Gas
- Two-Element Mixture of Bose and Fermi Superfluids
- Observation of two-species vortex lattices in a mixture of mass-imbalance Bose and Fermi superfluids
- Trimers, molecules and polarons in imbalanced atomic Fermi gases
- Resonantly Interacting Fermions In a Box
- Polarons in Ultracold Fermi Superfluids
- Lattice Monte Carlo calculations for unitary fermions in a finite box
- Polaronic atom-trimer continuity in three-component Fermi gases
- 1S0 Proton and Neutron Superfluidity in beta-stable Neutron Star Matter
- Time-resolved observation of competing attractive and repulsive short-range correlations in strongly interacting Fermi gases
- Andreev-Bashkin effect in superfluid cold gases mixture
- Dynamic structure factor of a superfluid Fermi gas
- Spin dynamics and Andreev-Bashkin effect in mixtures of one-dimensional Bose gases
- Few vs many-body physics of an impurity immersed in a superfluid of spin 1/2 attractive fermions
Cited by in corpus (4)
- Heavy polarons in ultracold atomic Fermi superfluids at the BEC-BCS crossover: formalism and applications
- Exact quasiparticle properties of a heavy polaron in BCS Fermi superfluids
- Universal van der Waals Force Between Heavy Polarons in Superfluids
- Exploring beyond-mean-field logarithmic divergences in Fermi-polaron energy