Peaks and widths of radio-frequency spectra: An analysis of the phase diagram of ultra-cold Fermi gases
arXiv:2311.00479 · doi:10.1016/j.rinp.2024.107358
Abstract
We provide a comprehensive theoretical study of the radio-frequency (rf) spectra of a two-component Fermi gas with balanced populations in the normal region of the temperature-vs-coupling phase diagram. In particular, rf spectra are analyzed in terms of two characteristic peaks, which can be either distinct or overlapping. On the BEC side of the crossover, these two contributions are associated with a fermionic quasi-particle peak and a bosonic-like contribution due to pairing. On the BCS side of the crossover, the two peaks are instead associated with interactions between particles occurring, respectively, at high or low relative momenta. Through this two-peak analysis, we show how and to what extent the correlation between the widths of the rf spectra and the pair size, previously identified in the superfluid phase at low temperature, can be extended to the normal phase, as well as how the temperature-vs-coupling phase diagram of the BCS-BEC crossover can be partitioned in a number of distinct physical sectors. Several analytic results for the shape and widths of the rf spectra are also derived in appropriate temperature and coupling limits.
arXiv comment23 pages, 16 figures
References in corpus (62)
- Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
- Creation of ultracold molecules from a Fermi gas of atoms
- Revealing the Superfluid Lambda Transition in the Universal Thermodynamics of a Unitary Fermi Gas
- Using photoemission spectroscopy to probe a strongly interacting Fermi gas
- Measurement of positive and negative scattering lengths in a Fermi gas of atoms
- Observation of pseudogap behavior in a strongly interacting Fermi gas
- Radio-Frequency Spectroscopy of Ultracold Fermions
- The BCS-BEC crossover: From ultra-cold Fermi gases to nuclear systems
- Homogeneous Atomic Fermi Gases
- Pseudogap and spectral function from superconducting fluctuations to the bosonic limit
- Determination of the Superfluid Gap in Atomic Fermi Gases by Quasiparticle Spectroscopy
- On the correct strong-coupling limit in the evolution from BCS superconductivity to Bose-Einstein condensation
- Tracking the Footprints of Spin Fluctuations: A MultiMethod, MultiMessenger Study of the Two-Dimensional Hubbard Model
- Spectral Functions and rf Response of Ultracold Fermionic Atoms
- Virial expansion for a strongly correlated Fermi gas
- Viscosity and scale invariance in the unitary Fermi gas
- Evolution from BCS Superconductivity to Bose Condensation: Analytic Results for the crossover in three dimensions
- Two-Dimensional Homogeneous Fermi Gases
- Tomographic RF Spectroscopy of a Trapped Fermi Gas at Unitarity
- Fermi polarons in two dimensions
- Boiling a Unitary Fermi Liquid
- BCS-BEC crossover at finite temperature in the broken-symmetry phase
- Pairing gap and in-gap excitations in trapped fermionic superfluids
- Determination of the Fermion Pair Size in a Resonantly Interacting Superfluid
- Theory of RF-spectroscopy of strongly interacting Fermions
- Evolution of the Normal State of a Strongly Interacting Fermi Gas from a Pseudogap Phase to a Molecular Bose Gas
- Viscous relaxation and collective oscillations in a trapped Fermi gas near the unitarity limit
- Virial expansion for a strongly correlated Fermi system and its application to ultracold atomic Fermi gases
- Shear viscosity and damping for a Fermi gas in the unitarity limit
- Breakdown of Fermi liquid description for strongly interacting fermions
- Radio-Frequency Transitions on Weakly-Bound Ultracold Molecules
- Spectral response and contact of the unitary Fermi gas
- Coherence and clock shifts in ultracold Fermi gases with resonant interactions
- Enhanced paraconductivity-like fluctuations in the radio frequency spectra of ultracold Fermi atoms
- Contact and sum-rules in a near-uniform Fermi gas at unitarity
- Single-particle excitations in a trapped gas of Fermi atoms in the BCS-BEC crossover region
- Virial expansion with Feynman diagrams
- Self-consistent theory for molecular instabilities in a normal degenerate Fermi gas in the BEC-BCS crossover
- Radio frequency spectroscopy and the pairing gap in trapped Fermi gases
- Spin-correlation functions in ultracold paired atomic-fermion systems: sum rules, self-consistent approximations, and mean fields
- Broad versus narrow Fano-Feshbach resonances in the BCS-BEC crossover with trapped Fermi atom
- Pair Correlations in the Two-Dimensional Fermi Gas
- Twin peaks in rf spectra of Fermi gases at unitarity
- Pairing effects in the normal phase of a two-dimensional Fermi gas
- Competition between final-state and pairing-gap effects in the radio-frequency spectra of ultracold Fermi atoms
- Fermi gas throughout the BCS-BEC crossover: Comparative study of t-matrix approaches with various degrees of self-consistency
- Pair fluctuation induced pseudogap in the normal phase of the two-dimensional attractive Hubbard model at weak coupling
- Photoemission spectrum and effect of inhomogeneous pairing fluctuations in the BCS-BEC crossover regime of an ultracold Fermi gas
- Physics of ultracold Fermi gases revealed by spectroscopies
- Temperature dependence of the pair coherence and healing lengths for a fermionic superfluid throughout the BCS-BEC crossover
- The contact in the unitary Fermi gas across the superfluid phase transition
- Low-dimensional pairing fluctuations and pseudogapped photoemission spectrum in a trapped two-dimensional Fermi gas
- High-temperature expansion for interacting fermions
- High Sensitivity RF Spectroscopy of a Strongly-Interacting Fermi Gas
- Fermi polarons at finite temperature: Spectral function and rf-spectroscopy
- Absence of heating in a uniform Fermi gas created by periodic driving
- Pairing and the spin susceptibility of the polarized unitary Fermi gas in the normal phase
- Pairing and radio-frequency spectroscopy in two-dimensional Fermi gases
- Pairing-gap, pseudo-gap, and no-gap phases in the radio-frequency spectra of a trapped unitary 6Li gas
- Local Photoemission Spectra and Effects of Spatial Inhomogeneity in the BCS-BEC Crossover Regime of a Trapped Ultracold Fermi Gas
- Shift of the molecular bound state threshold in dense ultracold Fermi gases with Feshbach resonance
- Pair correlations in the normal phase of an attractive Fermi gas