Proximity Effect and Spontaneous Vortex Phase in Planar SF-Structures

TL;DR

This paper investigates how the proximity effect in superconductor-ferromagnet structures leads to oscillations in the critical temperature and induces a spontaneous vortex state, resulting in significant magnetoresistive effects.

Contribution

It provides new insights into the oscillatory behavior of the critical temperature and the emergence of a spontaneous vortex phase in planar SF structures due to proximity effects.

Findings

Critical temperature minimizes near a quarter of the oscillation period.

Spontaneous vortex state causes notable magnetoresistive effects.

Oscillations of the order parameter influence superconducting properties.

Abstract

The proximity effect in SF structures was examined. It is shown that, due to the oscillations of the induced superconducting order parameter in a ferromagnet, the critical temperature of an SF-bilayer becomes minimal when the thickness of the ferromagnetic layer is close to a quarter of the period of spatial oscillations. It is found that the spontaneous vortex state arisen in the superconductor due to the proximity of the magnetic domain structure of a ferromagnet brings about noticeable magnetoresistive effects.