Breakdown of Fourier's Law near the Superfluid Transition in 4He
Abstract
The behavior of the superfluid - normal fluid interface in 4He has been studied in the presence of a heat flux, Q-->, in the range 0.1<Q<6 erg s-1 cm-2. Fourier's Law, Q--> = -κ▽T, has been observed, for the first time, to break down very close to the interface. In the nonlinear region, κ depends on Q. Theoretical predictions, which do not take gravity into account, are compared with these experimental results. The predicted extent of the nonlinear region agrees well with the data; however, at lower Q, a systematic discrepancy is found that may be ascribed to the effect of gravity on the interface.
- Publication:
-
Physical Review Letters
- Pub Date:
- September 1998
- DOI:
- 10.1103/PhysRevLett.81.2474
- Bibcode:
- 1998PhRvL..81.2474D