Magnetic proximity effect at interface between a cuprate superconductor and an oxide spin valve

TL;DR

This study investigates the magnetic proximity effect at the interface between a cuprate superconductor and an oxide spin valve, revealing induced magnetic moments and their spatial characteristics through experimental and theoretical analysis.

Contribution

It provides experimental evidence and theoretical modeling of magnetic proximity effects at the superconductor-ferromagnet interface, highlighting the orbital reconstruction mechanism.

Findings

Magnetic moments are induced in the superconductor due to proximity effects.

The penetration length of magnetic moments exceeds the coherence length.

Orbital reconstruction is the dominant mechanism for induced magnetization.

Abstract

Heterostructures consisting of a cuprate superconductor YBa2Cu3O7x and a ruthenate/manganite (SrRuO3/La0.7Sr0.3MnO3) spin valve have been studied by SQUID magnetometry, ferromagnetic resonances and neutron reflectometry. It was shown that due to the influence of magnetic proximity effect a magnetic moment is induced in the superconducting part of heterostructure and at the same time the magnetic moment is suppressed in the ferromagnetic spin valve. The experimental value of magnetization induced in the superconductor has the same order of magnitude with the calculations based on the induced magnetic moment of Cu atoms due to orbital reconstruction at the superconductor-ferromagnetic interface. It corresponds also to the model that takes into account the change in the density of states at a distance of order of the coherence length in the superconductor. The experimentally obtained characteristic length of penetration of the magnetic moment into superconductor exceeds the coherence length for cuprate superconductor. This fact points on the dominance of the mechanism of the induced magnetic moment of Cu atoms due to orbital reconstruction.