Impurity with a resonance in the vicinity of the Fermi energy

• URL: http://arxiv.org/abs/2111.13570v2
• Date: Tue, 15 Mar 2022 13:51:00 GMT
• Title: Impurity with a resonance in the vicinity of the Fermi energy
• Authors: Mikhail Maslov, Mikhail Lemeshko, Artem G. Volosniev
• Abstract summary: We study an impurity with a resonance level whose energy 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.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We study an impurity with a resonance level whose energy 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.

Related papers

• Emergence of Sound in a Tunable Fermi Fluid [0.5804487044220691]
  We study transport properties of an interacting Fermi gas by measuring its density response to a periodic external perturbation. We observe the emergence of sound, and find that the experimental observations are quantitatively understood with a first-principle transport equation for the FL. Our study establishes this system as a clean platform for studying Landau's theory of the FL and paves the way for extending the theory to more exotic conditions.
  arXiv  Detail & Related papers  (2024-07-18T17:59:52Z)
• Probing pair correlations in Fermi gases with Ramsey-Bragg interferometry [41.94295877935867]
  We propose an interferometric method to probe pair correlations in a gas of spin-1/2 fermions. The method consists of a Ramsey sequence where both spin states of the Fermi gas are set in a superposition of a state at rest and a state with a large recoil velocity. The off-diagonal long-range order is directly reflected in the behavior of the interferometric signal for long interrogation times.
  arXiv  Detail & Related papers  (2023-12-21T15:46:29Z)
• Observation and quantification of pseudogap in unitary Fermi gases [13.227049854625527]
  We report the observation of the long-sought pair-fluctuation-driven pseudogap in homogeneous unitary Fermi gases of lithium-6 atoms. The inverse pair lifetime exhibits a thermally-activated exponential behavior, uncovering the microscopic virtual pair breaking and recombination mechanism. Our findings quantitatively characterize the pseudogap in strongly-interacting Fermi gases, highlighting the role of preformed pairing as a precursor to superfluidity.
  arXiv  Detail & Related papers  (2023-10-21T14:35:36Z)
• The strongly driven Fermi polaron [49.81410781350196]
  Quasiparticles are emergent excitations of matter that underlie much of our understanding of quantum many-body systems. We take advantage of the clean setting of homogeneous quantum gases and fast radio-frequency control to manipulate Fermi polarons. We measure the decay rate and the quasiparticle residue of the driven polaron from the Rabi oscillations between the two internal states.
  arXiv  Detail & Related papers  (2023-08-10T17:59:51Z)
• Momentum space entanglement of interacting fermions [0.0]
  Momentum space entanglement entropy probes quantum correlations in interacting fermionic phases. We show that the R'enyi entropy in momentum space has a systematic expansion in terms of the phase space volume of the partition.
  arXiv  Detail & Related papers  (2022-03-15T18:00:00Z)
• Phase Transitions of Repulsive Two-Component Fermi Gases in Two Dimensions [0.0]
  We predict phase separations of two-dimensional Fermi gases with repulsive contact-type interactions between two spin components. We reveal a universal transition from the paramagnetic state at small repulsive interactions towards ferromagnetic density profiles. We uncover a zoo of metastable configurations that are energetically comparable to the ground-state density profiles.
  arXiv  Detail & Related papers  (2021-06-02T10:45:33Z)
• Stability and breakdown of Fermi polarons in a strongly interacting Fermi-Bose mixture [1.038987460834095]
  We investigate an imbalanced mixture of bosonic $41$K impurities immersed in a Fermi sea of ultracold $6$Li atoms. We find that the energy of the Fermi polarons formed in the thermal fraction of the impurity cloud remains rather insensitive to the impurity concentration. A closer investigation of the behavior of the condensate by means of Rabi oscillation measurements support this observation.
  arXiv  Detail & Related papers  (2021-03-05T12:08:42Z)
• Enhanced decoherence for a neutral particle sliding on a metallic surface in vacuum [68.8204255655161]
  We show that non-contact friction enhances the decoherence of the moving atom. We suggest that measuring decoherence times through velocity dependence of coherences could indirectly demonstrate the existence of quantum friction.
  arXiv  Detail & Related papers  (2020-11-06T17:34:35Z)
• Analog cosmological reheating in an ultracold Bose gas [58.720142291102135]
  We quantum-simulate the reheating-like dynamics of a generic cosmological single-field model in an ultracold Bose gas. Expanding spacetime as well as the background oscillating inflaton field are mimicked in the non-relativistic limit. The proposed experiment has the potential of exploring the evolution up to late times even beyond the weak coupling regime.
  arXiv  Detail & Related papers  (2020-08-05T18:00:26Z)
• Density profile of a semi-infinite one-dimensional Bose gas and bound states of the impurity [62.997667081978825]
  We study the effect of the boundary on a system of weakly interacting bosons in one dimension. The quantum contribution to the boson density gives rise to small corrections of the bound state energy levels.
  arXiv  Detail & Related papers  (2020-07-21T13:12:33Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.