Spectral Response and Contact of the Unitary Fermi Gas
Name
PhysRevLett.122.203402.pdf
Description
Published version
Size
436.55 KB
Format
Adobe PDF
Checksum (MD5)
894dd2c45d0d47b69219598f0cca4986
Author(s)
Mukherjee, Biswaroop
Patel, Parth B
Yan, Zhenjie
Fletcher, Richard J
Struck, Julian
Zwierlein, Martin W
Date Issued
2019
Journal
Physical Review Letters
Publisher
American Physical Society (APS)
Version
Final published version
Abstract
© 2019 American Physical Society. We measure radio frequency (rf) spectra of the homogeneous unitary Fermi gas at temperatures ranging from the Boltzmann regime through quantum degeneracy and across the superfluid transition. For all temperatures, a single spectral peak is observed. Its position smoothly evolves from the bare atomic resonance in the Boltzmann regime to a frequency corresponding to nearly one Fermi energy at the lowest temperatures. At high temperatures, the peak width reflects the scattering rate of the atoms, while at low temperatures, the width is set by the size of fermion pairs. Above the superfluid transition, and approaching the quantum critical regime, the width increases linearly with temperature, indicating non-Fermi-liquid behavior. From the wings of the rf spectra, we obtain the contact, quantifying the strength of short-range pair correlations. We find that the contact rapidly increases as the gas is cooled below the superfluid transition.
MIT Department
MIT-Harvard Center for Ultracold Atoms
Massachusetts Institute of Technology. Research Laboratory of Electronics
Massachusetts Institute of Technology. Department of Physics
Terms of Use
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DOI of Published Version
https://doi.org/10.1103/PHYSREVLETT.122.203402
