Spectral function of Fermi polarons at finite temperature from a self-consistent many-body $T$-matrix approach in real frequency

Abstract

We theoretically examine the finite-temperature spectral function of Fermi polarons in three dimensions, by using a self-consistent many-body $T$-matrix theory in real frequency. In comparison with the previous results from a non-self-consistent many-body $T$-matrix approach, we show that the treatment of self-consistency in the impurity Green function leads to notable changes in almost all the dynamical quantities, including the vertex function, impurity self-energy and spectral function. Eventually, it gives rise to quantitatively different predictions for the measurable radio-frequency spectrum and Raman spectrum at finite temperature. Using the recent spectroscopic measurements as a benchmark, we find that the self-consistent many-body $T$-matrix theory somehow provides a better explanation for the experimental data. The notable difference in the predictions from the non-self-consistent and self-consistent theories suggests that more accurate theoretical descriptions are needed, in order to fully account for the current spectroscopic observations on Fermi polarons.

12 pages, 13 figures

References in corpus (17)

• Many-Body Physics with Ultracold Gases
• Observation of Fermi Polarons in a Tunable Fermi Liquid of Ultracold Atoms
• Attractive and repulsive Fermi polarons in two dimensions
• Fermi-Polaron: Diagrammatic Monte Carlo for Divergent Sign-Alternating Series
• Repulsive Fermi polarons in a resonant mixture of ultracold ${}^6$Li atoms
• Time dependent impurity in ultracold fermions: orthogonality catastrophe and beyond
• Highly polarized Fermi gases in two dimensions
• Comparative study of strong coupling theories of a trapped Fermi gas at unitarity
• Diagrammatic Monte Carlo study of mass-imbalanced Fermi-polaron system
• 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
• Crossover polarons in a strongly interacting Fermi superfluid
• Fermi polarons at finite temperature: Spectral function and rf-spectroscopy
• Intersections of ultracold atomic polarons and nuclear clusters: How is a chart of nuclides modified in dilute neutron matter?
• Two-dimensional coherent spectroscopy of trion-polaritons and exciton-polaritons in atomically thin transition metal dichalcogenides
• Thermally stable p-wave repulsive Fermi polaron without a two-body bound state
• Raman spectroscopy of Fermi polarons

Cited by in corpus (2)

• Mass-gap description of heavy impurities in Fermi gases
• Momentum-dependent quasiparticle properties of the Fermi polaron from the functional renormalization group