Conductance fluctuations in metallic nanogaps made by electromigration

TL;DR

This paper investigates quantum conductance fluctuations in gold nanogaps created by electromigration, analyzing how bias voltage and magnetic field influence electron interference and phase coherence at low temperatures.

Contribution

It introduces a method to analyze conductance fluctuations to determine electron trajectory types and phase coherence times in electromigrated nanogaps.

Findings

Quantum interference causes conductance fluctuations dependent on bias and magnetic field.

Correlation functions reveal electron trajectory types responsible for interference.

Phase coherence time is quantified in the nanogap devices.

Abstract

We report on low temperature conductance measurements of gold nanogaps fabricated by controlled electromigration. Fluctuations of the conductance due to quantum interferences and depending both on bias voltage and magnetic field are observed. By analyzing the voltage and magnetoconductance correlation functions we determine the type of electron trajectories generating the observed quantum interferences and the effective characteristic time of phase coherence in our device.