Point-Contact Study of Fast and Slow Two-Level Fluctuators in Metallic Glasses

Abstract

Distinct peaks in the differential resistance of point contacts of metallic glasses have been observed around zero bias. These peaks can be attributed to the interaction between conduction electrons and fast switching two-level fluctuators (TLF). Discrete jumps between two such peaks were found to occur, which can be explained by a modulation of the electron-TLF coupling by defects, present in the vicinity of the contact, that slowly switch between two configurations.