# Electromagnetic proximity effect controlled by spin-triplet correlations in superconducting spin-valve structures

## TL;DR

This paper demonstrates how spin-triplet correlations in superconducting spin valves significantly enhance the electromagnetic proximity effect, enabling long-range magnetic field leakage and control of magnetic states in layered structures, with implications for measuring spontaneous magnetic fields.

## Contribution

It provides a theoretical analysis of the electromagnetic proximity effect driven by spin-triplet correlations, explaining experimental observations and proposing new ways to control magnetic states in superconductor-ferromagnet systems.

## Key findings

- Spin-triplet correlations enhance electromagnetic proximity effect.
- Long-range magnetic field leakage from ferromagnet to superconductor.
- Control of magnetic states via superconductivity in layered structures.

## Abstract

The spin-triplet correlations in superconducting spin valve structures arising in the presence of noncollinear textures of magnetic moment are shown to enhance strongly the electromagnetic proximity effect, i. e. the long-range leakage of the magnetic field from the ferromagnet (F) to the superconducting (S) layer. Both the dirty and clean limits are studied on the basis of the Usadel and Eilenberger theory, correspondingly. Our results suggest a natural explanation for the puzzling enhancement of the spontaneous magnetic fields induced by the noncollinear magnetic structures observed by the muon spin rotation techniques in a wide class of layered S/F systems. We show that the electromagnetic proximity effect causes the shift of the Fraunhofer dependence of the critical current on the external magnetic field in the Josephson junction with one superconducting electrode covered by the ferromagnetic layer. This provides an alternative way to measure both the magnitude and the direction of the spontaneous magnetic field induced in the superconductor. We also demonstrate the possibility of the long ranged superconductivity control of the magnetic state in F$_1$/S/F$_2$ structures.