Ultra-strong photon-to-magnon coupling in multilayered heterostructures involving superconducting coherence via ferromagnetic layers

TL;DR

This paper presents a novel multilayered heterostructure design that achieves ultra-strong photon-to-magnon coupling, enabling scalable hybrid magnonic systems for quantum technology applications.

Contribution

It introduces a flexible multilayered approach that significantly enhances coupling strength through reduced photon mode volume and superconducting coherence in ferromagnetic layers.

Findings

Achieved unprecedented photon-magnon coupling strength.

Demonstrated long-range superconducting coherence via ferromagnetic layers.

Enabled potential for scalable on-chip hybrid magnonic systems.

Abstract

The critical step for future quantum industry demands realization of efficient information exchange between different-platform hybrid systems, including photonic and magnonic systems, that can harvest advantages of distinct platforms. The major restraining factor for the progress in certain hybrid systems is the fundamentally weak coupling parameter between the elemental particles. This restriction impedes the entire field of hybrid magnonics by making realization of scalable on-chip hybrid magnonic systems unattainable. In this work, we propose a general flexible approach for realization of on-chip hybrid magnonic systems with unprecedentedly strong coupling parameters. The approach is based on multilayered micro-structures containing superconducting, insulating and ferromagnetic layers with modified both photon phase velocities and magnon eigen-frequencies. Phenomenologically, the enhanced coupling strength is provided by the radically reduced photon mode volume. The microscopic mechanism of the phonon-to-magnon coupling in studied systems evidences formation of the long-range superconducting coherence via thick strong ferromagnetic layers. This coherence is manifested by coherent superconducting screening of microwave fields by the superconductor/ferromagnet/superconductor three-layers in presence of magnetization precession. This discovery offers new opportunities in microwave superconducting spintronics for quantum technologies.