Spin pumping driven by magnon-polaritons in a ferromagnet-coplanar superconducting resonator hybrid system

TL;DR

This paper demonstrates spin pumping driven by a strongly coupled magnon-photon system in a ferromagnet-superconductor hybrid, revealing mode splitting, linewidth broadening, and nonlinear effects at high power.

Contribution

It introduces a novel hybrid system combining ferromagnets and superconducting resonators to electrically detect magnon-photon coupling via spin pumping.

Findings

Electrical detection of strong magnon-photon coupling through inverse spin-Hall effect.

Observation of mode splitting and linewidth broadening indicating strong coupling.

Coupling strength decreases with increasing microwave power, showing nonlinear effects.

Abstract

We demonstrate spin pumping driven by a strongly coupled magnon-photon system using a ferromagnet-coplanar superconducting resonator hybrid system at 1.4 K. Electrical readout via the inverse spin-Hall effect reveals characteristic coupling features, including mode splitting and linewidth broadening, demonstrating the electrical detection of strongly coupled microwave photons and magnons. The magnon-photon coupling strength obtained by combined spin pumping and inverse spin-Hall effect measurements is compared to microwave transmission experiments. Furthermore, microwave power-dependent measurements reveal a decrease in the coupling strength with increasing microwave power alongside the onset of nonlinearities of the superconducting resonator above a critical microwave power threshold.