Universal dynamic structure factor of a strongly correlated Fermi gas

Abstract

Universality of strongly interacting fermions is a topic of great interest in diverse fields. Here we investigate theoretically the universal dynamic density response of resonantly interacting ultracold Fermi atoms in the limit of either high temperature or large frequency: (1) At high temperature, we use quantum virial expansion to derive universal, non-perturbative expansion functions of dynamic structure factor; (2) At large momentum, we identify that the second-order expansion function gives the Wilson coefficient used in the operator expansion product method. The dynamic structure factor is therefore determined by its second-order expansion function with an overall normalization factor given by Tan's contact parameter. We show that the spin parallel and antiparallel dynamic structure factors have respectively a tail of the form $\sim \pm {\omega }^{-5/2}$ for $\omega \to \infty$, decaying slower than the total dynamic structure factor found previously ($\sim {\omega }^{-7/2}$). Our predictions for dynamic structure factor at high temperature or large frequency are testable using Bragg spectroscopy for ultracold atomic Fermi gases.

5 pages, 4 figures

References in corpus (25)

• Theory of ultracold Fermi gases
• Exploring the Thermodynamics of a Universal Fermi Gas
• Generalized Virial Theorem and Pressure Relation for a strongly correlated Fermi gas
• Exact Relations for a Strongly-interacting Fermi Gas from the Operator Product Expansion
• Universal behavior of pair correlations in a strongly interacting Fermi gas
• Bragg spectroscopy of a strongly interacting Fermi gas
• Virial expansion for a strongly correlated Fermi gas
• Measurement of the Entropy and Critical Temperature of a Strongly Interacting Fermi Gas
• The potential energy of a ${}^{40}$K Fermi gas in the BCS-BEC crossover
• Universal Relations for Identical Bosons from 3-Body Physics
• Viscosity of strongly interacting quantum fluids: spectral functions and sum rules
• Short-Time Operator Product Expansion for rf Spectroscopy of a Strongly-interacting Fermi Gas
• Critical Temperature Curve in the BEC-BCS Crossover
• Three attractively interacting fermions in a harmonic trap: Exact solution, ferromagnetism, and high-temperature thermodynamics
• Pseudo-gap pairing in ultracold Fermi atoms
• Pairing and Superfluid Properties of Dilute Fermion Gases at Unitarity
• Short-distance and short-time structure of a unitary Fermi gas
• Enhanced paraconductivity-like fluctuations in the radio frequency spectra of ultracold Fermi atoms
• Universal contact of strongly interacting fermions at finite temperatures
• Universal thermodynamics of a strongly interacting Fermi gas: theory versus experiment
• Energy spectrum of harmonically trapped two-component Fermi gases: Three- and Four-Particle Problem
• Static structure factor of a strongly correlated Fermi gas at large momenta
• Establishing the Presence of Coherence in Atomic Fermi Superfluids: Spin-Flip and Spin-Preserving Bragg Scattering at Finite Temperatures
• Dynamical Cluster Quantum Monte Carlo Study of the Single Particle Spectra of Strongly Interacting Fermion Gases
• Dynamic response of strongly correlated Fermi gases in the quantum virial expansion

Cited by in corpus (15)

• Virial expansion for a strongly correlated Fermi system and its application to ultracold atomic Fermi gases
• Quantum Monte Carlo approaches to nuclear and atomic physics
• Contact and sum-rules in a near-uniform Fermi gas at unitarity
• Pseudogaps in strongly interacting Fermi gases
• Dynamic spin response of a strongly interacting Fermi gas
• Probing strongly interacting atomic gases with energetic atoms
• Low-momentum dynamic structure factor of a strongly interacting Fermi gas at finite temperature: The Goldstone phonon and its Landau damping
• Dynamical structure factors of a two-dimensional Fermi superfluid within random phase approximation
• Dynamic structure factor of a strongly correlated Fermi superfluid within a density functional theory approach
• Spin-dependent Bragg spectroscopy of a spinor Bose gas
• Dynamic structure function of a cold Fermi gas at unitarity
• Photo-excitation measurement of Tan's contact for a strongly interacting Fermi gas
• Density and Spin Linear Response of Atomic Fermi Superfluids with Population Imbalance in BCS-BEC Crossover
• Response function of strongly interacting Fermi gas in a virial expansion
• Establishing the Gauge Invariant Linear Response of Fermionic Superfluids with Pair Fluctuations: A Diagrammatic approach