We study an impurity with a resonance level whose position coincides with the Fermi energy of the surrounding Fermi gas. An impurity causes a rapid variation of the scattering phase shift for fermions at the Fermi surface, introducing a new characteristic length scale into the problem. We investigate manifestations of this length scale in the self-energy of the impurity and in the density of the bath. Our calculations reveal a model-independent deformation of the density of the Fermi gas, which is determined by the width of the resonance. To provide a broader picture, we investigate time evolution of the density in quench dynamics, and study the behavior of the system at finite temperatures. Finally, we briefly discuss implications of our findings for the Fermi-polaron problem.
Physical Review Research
M.L. acknowledges support by the Austrian Science Fund (FWF), under Project No. P29902-N27, and by the European Research Council (ERC) starting Grant No. 801770 (ANGULON). A.G.V. acknowledges support by European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 754411.
Maslov M, Lemeshko M, Volosniev A. Impurity with a resonance in the vicinity of the Fermi energy. Physical Review Research. 2022;4. doi:10.1103/PhysRevResearch.4.013160
Maslov, M., Lemeshko, M., & Volosniev, A. (2022). Impurity with a resonance in the vicinity of the Fermi energy. Physical Review Research. American Physical Society. https://doi.org/10.1103/PhysRevResearch.4.013160
Maslov, Mikhail, Mikhail Lemeshko, and Artem Volosniev. “Impurity with a Resonance in the Vicinity of the Fermi Energy.” Physical Review Research. American Physical Society, 2022. https://doi.org/10.1103/PhysRevResearch.4.013160.
M. Maslov, M. Lemeshko, and A. Volosniev, “Impurity with a resonance in the vicinity of the Fermi energy,” Physical Review Research, vol. 4. American Physical Society, 2022.
Maslov M, Lemeshko M, Volosniev A. 2022. Impurity with a resonance in the vicinity of the Fermi energy. Physical Review Research. 4, 013160.
Maslov, Mikhail, et al. “Impurity with a Resonance in the Vicinity of the Fermi Energy.” Physical Review Research, vol. 4, 013160, American Physical Society, 2022, doi:10.1103/PhysRevResearch.4.013160.
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