Contact and sum-rules in a near-uniform Fermi gas at unitarity

Abstract

We present an experimental study of the high-energy excitation spectra of unitary Fermi gases. Using focussed beam Bragg spectroscopy, we locally probe atoms in the central region of a harmonically trapped cloud where the density is nearly uniform, enabling measurements of the dynamic structure factor for a range of temperatures both below and above the superfluid transition. Applying sum-rules to the measured Bragg spectra, we resolve the characteristic behaviour of the universal contact parameter, $\mathcal{C}$, across the superfluid transition. We also employ a recent theoretical result for the kinetic (second-moment) sum-rule to obtain the internal energy of gases at unitarity.

5 pages, 4 figures

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Cited by in corpus (8)

• Spectral response and contact of the unitary Fermi gas
• The fourth- and fifth-order virial coefficients from weak-coupling to unitarity
• Probing the supersolid order via high-energy scattering: analytical relations among response, density modulation, and superfluid fraction
• High Temperature Virial Expansion to Universal Quench Dynamics
• Equation of State of Neutron-Rich Matter in $d$-Dimensions
• P-wave contacts of quantum gases in quasi-one-dimensional and quasi-two-dimensional traps
• Photo-excitation measurement of Tan's contact for a strongly interacting Fermi gas
• Equivalence of dissipative and dissipationless dynamics of interacting quantum systems with its application to the unitary Fermi gas