Non linear excess conductivity of Bi$_2$Sr$_2$Ca$_{n-1}$Cu$_n$O$_{2n+4+x}$ (n = 1,2), thin films

TL;DR

This study investigates how electric fields suppress excess conductivity in Bi-based cuprate thin films, revealing a lower-than-expected characteristic field and a scaling behavior similar to magnetic field effects.

Contribution

It demonstrates a novel pulse-probe method to measure electric field effects on excess conductivity and identifies a universal scaling behavior in these materials.

Findings

Characteristic electric field is below expected values.

Scaling of excess conductivity with electric field and temperature.

Similar scaling behavior to magnetic field effects.

Abstract

The suppression of excess conductivity with electric field is studied for Bi$_2$Sr$_2$Ca$_{n-1}$Cu$_n$O$_{2n+4+x}$ ($n$ = 1, 2) thin films. A pulse-probe technique is used, which allows for an estimate of the sample temperature. The characteristic electric field for fluctuations suppression is found well below the expected value for all samples. For the $n=1$ material, a scaling of the excess conductivity with electric field and temperature is obtained, similar to the scaling under strong magnetic field.