Intrinsic Josephson junction characteristics of Nd2-xCexCuO4/SrTiO3 epitaxial films

TL;DR

This study investigates the intrinsic Josephson junction behavior in Nd2-xCexCuO4/SrTiO3 epitaxial films, revealing multiple resistive states and insights into the tunneling mechanism and order parameter symmetry in these superconducting materials.

Contribution

It provides experimental evidence of intrinsic Josephson junction characteristics and discusses the nature of the order parameter in Nd2-xCexCuO4 films, advancing understanding of their superconducting properties.

Findings

Multiple resistive branches in I-V characteristics indicate intrinsic Josephson junctions.

Evidence supports tunneling between CuO2 layers as the mechanism.

Nonmonotonic order parameter suggests coexistence of superconductivity and antiferromagnetic fluctuations.

Abstract

The current-voltage (I-V) properties along the c axis on Nd2-xCexCuO4 /SrTiO3 epitaxial films with x = 0.145, 0.15 were investigated. For all the samples it has been established that the I-V characteristics exhibit several resistive branches, which correspond to the resistive states of individual Josephson junctions. The results confirm the idea of a tunneling mechanism between the CuO2 layers (superconductor - insulator - superconductor junction) for the investigated Nd2-xCexCuO4 compound. The I-V dependence of this compound with x = 0.15 points out on the nonmonotonic nature of the d-wave or anisotropic s-wave symmetry order parameter associated with the coexistence of superconductivity and antiferromagnetic fluctuations.