Anomalous Enhancement of the Superconducting Transition Temperature in Electron-Doped Cuprate Heterostructures

TL;DR

This study demonstrates a significant increase in the superconducting transition temperature in multilayer electron-doped cuprate heterostructures due to charge redistribution across layers.

Contribution

It reveals that multilayer heterostructures of electron-doped cuprates exhibit enhanced $T_{c}$ driven by charge redistribution, a novel mechanism for superconductivity enhancement.

Findings

$T_{c}$ increases in multilayer heterostructures compared to single-phase films.

Charge redistributes over large distances within the heterostructures.

Critical current density measurements support the charge redistribution mechanism.

Abstract

The superconducting transition temperature $T_{c}$ of multilayers of electron-doped cuprates, composed of underdoped (or undoped) and overdoped La% $_{2-x}$Ce$_{x}$CuO$_{4}$ (LCCO) and Pr$_{2-x}$Ce$_{x}$CuO$_{4}$ (PCCO) thin films, is found to increase significantly with respect to the $T_{c}$ of the corresponding single-phase films. By investigating the critical current density of superlattices with different doping levels and layer thicknesses, we find that the $T_{c}$ enhancement is caused by a redistribution of charge over an anomalously large distance.