Abstract
Various experiments on the propagation of high-frequency phonons in liquid at K lead to the conclusion that there is a critical wave vector such that phonons with wave vector have very short mean paths while those with have very long ones. As is adjustable over a wide range we recognize the possibility for phonon spectroscopy, using the helium as a tuneable high-pass phonon filter.
- Received 7 October 1974
DOI:https://doi.org/10.1103/PhysRevLett.33.1425
©1974 American Physical Society