Electric--field effect on electron-doped infinite-layer Sr$_{0.88}$La$_{0.12}$CuO$_{2+x}$ thin films

TL;DR

This study demonstrates that electric-field modulation of carrier density in Sr$_{0.88}$La$_{0.12}$CuO$_{2+x}$ thin films affects their resistivity and superconducting temperature, revealing complex electron-hole interactions in electron-doped cuprates.

Contribution

It introduces a novel electric-field technique to independently modulate electron and hole densities in electron-doped cuprate thin films, unlike traditional chemical doping.

Findings

Electric-field can tune surface resistivity and carrier types.

Superconducting transition temperature increases with electron transfer.

Hole contribution dominates normal state resistivity despite electron dominance in Hall effect.

Abstract

We have used the electric--field effect to modulate the resistivity of the surface of underdoped Sr$_{0.88}$La$_{0.12}$CuO$_{2+x}$ thin films, allowing opposite modifications of the electron and hole density in the CuO$_2$ planes, an original situation with respect to conventional chemical doping in electron-doped materials. When the Hall effect indicates a large contribution of a hole band, the electric--field effect on the normal state resistivity is however dominated by the electrons, and the superconducting transition temperature increases when carriers are transfered from holes to electrons.