Abstract
Experimental evidence is presented showing that the creation of vortices in He II involves macroscopic quantum tunneling through, or thermal activation over, a potential-energy barrier ε. The investigations, based on measurements of the rate at which negative ions create vortex rings in the isotopically pure superfluid within the temperature range 50<T<500 mK, have yielded a barrier height of ε/ K, in excellent agreement with the theoretical value predicted by Muirhead, Vinen, and Donnelly.
- Received 26 October 1987
DOI:https://doi.org/10.1103/PhysRevLett.60.604
©1988 American Physical Society