Non linear transport properties of an insulating YBCO nano-bridge

TL;DR

This study investigates the nonlinear transport behavior of an insulating YBCO nano-bridge, revealing variable-range hopping, random telegraph noise from individual fluctuators, and complex multi-level resistance fluctuations.

Contribution

It provides new insights into the fluctuation dynamics and noise characteristics of insulating YBCO nanostructures at the nanoscale.

Findings

Transport is nonlinear as expected for variable-range hopping insulators.

Observation of individual fluctuators generating random telegraph noise.

Detection of three-level resistance fluctuations indicating complex charge trap dynamics.

Abstract

We have investigated the transport properties of an insulating sub-micrometric YBa2Cu3O7-d bridge, patterned on a thin film. As expected for a variable-range-hopping insulator, transport is found non linear. The reduced dimension allows for the observation of an individual fluctuator generating random telegraph noise, which dynamics could be explored as a function of the temperature and transport current. Some recordings clearly exhibit three levels fluctuating resistance, with comparable level separation and correlated dynamics, which likely result from the existence of two states or correlated clustered charge traps.