Relaxation of two-level systems and sound absorption in metallic glasses
Kagan Yu. , Prokof'ev N. V.
A general theory of relaxation of two-level systems in an amorphous metal, with allowance for the tunneling-induced electron polaron effect, is developed. The anomalous behavior of the absorption of a low-frequency sound resulting from the transition to the superconducting state, which was observed in Refs. 1 and 2, is explained.