RELAXATION OF 2-LEVEL FLUCTUATORS IN POINT CONTACTS

The contributions by three different mechanisms of interactions betwee n electrons and two-level fluctuators to the low-energy singularity pr esent in point-contact spectra of metallic glasses have been studied b y measuring rf response signals at 600 MHz and 60 GHz, and the low-fre quency response at 1.85 kHz. The resulting curves indicate that a nonm agnetic Kondo-like interaction is the most important contribution, but , depending on the exact shape of the background signal due to electro n-phonon and electron-electron interactions, elastic scattering on hig hly asymmetric two-level fluctuators may also be quite important. [S01 63-1829(98)01927-4].