Observation of suppressed viscosity in the normal state of <sup>3</sup>He due to superfluid fluctuations.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37730714.
- Also identified by DOI 10.1038/s41467-023-41422-3 and PMC identifier 10511454.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Evidence of fluctuations in transport have long been predicted in <sup>3</sup>He. They are expected to contribute only within 100μK of T<sub>c</sub> and play a vital role in the theoretical modeling of ordering; they encode details about the Fermi liquid parameters, pairing symmetry, and scattering phase shifts. It is expected that they will be of crucial importance for transport probes of the topologically nontrivial features of superfluid <sup>3</sup>He under strong confinement. Here we characterize the temperature and pressure dependence of the fluctuation signature, by monitoring the quality factor of a quartz tuning fork oscillator. We have observed a fluctuation-driven reduction in the viscosity of bulk <sup>3</sup>He, finding data collapse consistent with the predicted theoretical behavior.