Non-linear electrical conduction and broadband noise in charge-ordered rare earth manganate Nd_0.5Ca_0.5MnO_3

TL;DR

This study investigates the non-linear electrical conduction and broadband noise in charge-ordered Nd_0.5Ca_0.5MnO_3 films, revealing a threshold field for conduction and noise that diminishes near the charge ordering temperature.

Contribution

It demonstrates the existence of a threshold field inducing non-linear conduction and broadband noise in charge-ordered manganate films, linking depinning to the onset of non-linearity.

Findings

Threshold field triggers non-linear conduction.

Broadband noise correlates with non-linear conduction.

Depinning occurs at the charge ordering temperature.

Abstract

Measurements of the dc transport properties and the low-frequency conductivity noise in films of charge ordered Nd_0.5Ca_0.5MnO_3 grown on Si subtrate reveal the existence of a threshold field in the charge ordered regime beyond which strong non linear conduction sets in along with a large broad band conductivity noise. Threshold-dependent conduction disappears as T -> T_{CO}, the charge ordering temperature. This observation suggests that the charge ordered state gets depinned at the onset of the non-linear conduction.