Abstract
Measurements of the velocity of third sound on films as thin as 2.1 atomic layers yield the healing length of superfluid He II down to temperatures of 0.1 K. It is argued that these films are two-dimensional superfluids.
- Received 23 August 1973
DOI:https://doi.org/10.1103/PhysRevLett.32.147
©1974 American Physical Society