Please use this identifier to cite or link to this item:
https://hdl.handle.net/2440/139763
Citations | ||
Scopus | Web of Science® | Altmetric |
---|---|---|
?
|
?
|
Type: | Journal article |
Title: | High-Frequency Sound in a Unitary Fermi Gas |
Author: | Kuhn, C.C.N. Hoinka, S. Herrera, I. Dyke, P. Kinnunen, J.J. Bruun, G.M. Vale, C.J. |
Citation: | Physical Review Letters, 2020; 124(15):150401-1-150401-6 |
Publisher: | American Physical Society |
Issue Date: | 2020 |
ISSN: | 0031-9007 1079-7114 |
Statement of Responsibility: | C. C. N. Kuhn, S. Hoinka, I. Herrera, P. Dyke, J. J. Kinnunen, G. M. Bruun, and C. J. Vale |
Abstract: | We present an experimental and theoretical study of the phonon mode in a unitary Fermi gas. Using two-photon Bragg spectroscopy, we measure excitation spectra at a momentum of approximately half the Fermi momentum, both above and below the superfluid critical temperature T_{c}. Below T_{c}, the dominant excitation is the Bogoliubov-Anderson (BA) phonon mode, driven by gradients in the phase of the superfluid order parameter. The temperature dependence of the BA phonon is consistent with a theoretical model based on the quasiparticle random phase approximation in which the dominant damping mechanism is via collisions with thermally excited quasiparticles. As the temperature is increased above T_{c}, the phonon evolves into a strongly damped collisional mode, accompanied by an abrupt increase in spectral width. Our study reveals strong similarities between sound propagation in the unitary Fermi gas and bosonic liquid helium. |
Description: | Published 13 April 2020 |
Rights: | © 2020 American Physical Society |
DOI: | 10.1103/PHYSREVLETT.124.150401 |
Grant ID: | http://purl.org/au-research/grants/arc/CE170100039 |
Published version: | http://dx.doi.org/10.1103/physrevlett.124.150401 |
Appears in Collections: | Physics publications |
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.