Superconductivity Mediated Long Range Magnetic Coupling

TL;DR

This paper investigates how ferromagnetic insulators on a Rashba superconductor thin film induce long-range magnetic interactions with unique static and dynamic properties, relevant for superconducting spintronics.

Contribution

It reveals that ferromagnetic insulators generate circular supercurrents enabling long-range magnetic interactions with distinct static and dynamic behaviors.

Findings

Long-range magnetic interactions decay as power laws.

Static interactions can be ferromagnetic, unlike previous exponential decay models.

Dynamic interactions exhibit different distance dependence.

Abstract

We study a Rashba superconductor thin film with ferromagnetic insulators (FIs) placed on top of it. We show that the ferromagnetic insulators generate circular super-currents, enabling long-range magnetic interactions (LRMI), decaying in power laws. In the static case, the long-range magnetic interaction can be ferromagnetic, in contrast to previous studies showing that superconductor mediates anti-ferromagnetic interactions decaying exponentially. Surprisingly, we find that in the dynamic case, the LRMI has a different distance dependence. Our results have potential applications in superconducting spintronics.