Hybrid magnetization dynamics in $\text{Cu}_\text{2}\text{OSeO}_\text{3}$/$\mathrm{NiFe}$ heterostructures

TL;DR

This study explores the hybrid magnetization dynamics in Cu2OSeO3/NiFe heterostructures, revealing a hybrid mode with unique anisotropic properties at cryogenic temperatures, advancing understanding of interface spin interactions.

Contribution

It introduces the observation of a hybrid magnetization mode in Cu2OSeO3/NiFe heterostructures and characterizes its anisotropic behavior, which was not previously documented.

Findings

Discovery of a hybrid mode below the helimagnetic transition temperature.

The hybrid mode exhibits predominantly four-fold anisotropy.

Resonance frequencies depend on in-plane magnetic field orientation.

Abstract

We investigate the coupled magnetization dynamics in heterostructures of a single crystal of the chiral magnet $\mathrm{Cu_2OSeO_3}$ (CSO) and a polycrystalline ferromagnet $\mathrm{NiFe}$ (Py) thin film using broadband ferromagnetic resonance (FMR) at cryogenic temperatures. We observe the excitation of a hybrid mode (HM) below the helimagnetic transition temperature of CSO. This HM is attributed to the spin dynamics at the CSO/Py interface. We study the HM by measuring its resonance frequencies for in plane rotations of the external magnetic field. We find that the HM exhibits dominantly four-fold anisotropy, in contrast to the FMR of CSO and Py.