In-plane angular dependence of the spin-wave nonreciprocity of an ultrathin film with Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates how the nonreciprocity of spin-wave propagation in ultrathin films with Dzyaloshinskii-Moriya interaction varies with in-plane angle, confirming analytical models and providing a new experimental method to measure the DMI constant.

Contribution

It introduces a magnon-dynamics based method to experimentally determine the DMI constant in multilayer thin films, validating it against existing dispersion relation measurements.

Findings

Frequency nonreciprocity shows sinusoidal dependence on in-plane angle.

The measured DMI constant agrees with previous dispersion relation studies.

The method provides a reliable way to quantify DMI in ultrathin films.

Abstract

The nonreciprocal propagation of spin waves in an ultrathin Pt/Co/Ni film has been measured by Brillouin light scattering. The frequency nonreciprocity, due to the interfacial Dzyaloshinskii-Moriya interaction (DMI), has a sinusoidal dependence on the in-plane angle between the magnon wavevector and the applied magnetic field. The results, which are in good agreement with analytical predictions reported earlier, yield a value of the DMI constant which is the same as that obtained previously from a study of the magnon dispersion relations. We have demonstrated that our magnon-dynamics based method can experimentally ascertain the DMI constant of multilayer thin films.