Fluctuator in disordered metallic point contacts: a simulation approach

TL;DR

This paper uses numerical simulations to study electron transport and low-frequency noise in amorphous metallic contacts, revealing multistable structural relaxations and their temperature-dependent behavior.

Contribution

It introduces a simulation approach to visualize and analyze the multistable structural modes responsible for noise in disordered metallic point contacts.

Findings

Identification of multistable structural relaxations affecting noise

Dependence of noise magnitude on mode size and structure

Observation of transition to complex behavior at low temperatures

Abstract

Electron transport through amorphous monatomic metallic structures generated earlier by molecular dynamics simulations is studied numerically. The interference of electronic trajectories backscattered by the structural disorder probes the multistable structural relaxations responsible for low-frequency noise in real metallic contacts. The structure of these modes is visualized; the dependence of noise magnitude on size and structure of the modes is studied. The transition from multistable behaviour to a more complex one is observed for temperatures far below the melting temperature. The current fluctuations observed numerically resemble the complex behaviour reported earlier for current noise in small metallic structures at moderate temperatures.