Mesoscopic Material Properties from Magnon Scattering in Thin Films

Existing scattering methods often require large samples in order to achieve an appreciable scattering intensity. Mesoscopic samples therefore pose a severe challenge to traditional scattering platforms, motivating the development of alternative table-top scattering techniques better suited to the study of such samples. Toward this end, we study the scattering of spin waves in magnetic thin films for application to our tabletop magnon scattering platform (1). Using NV center magnetometry, our experimental collaborators are able to resolve the amplitude and phase of spin waves scattered from a target material. We have been developing a procedure to invert this signal and yield properties of the scatterer. Properties of interest can be as simple as the shape and magnetic character of the target, or as complex as its magnetic excitation spectrum. This procedure is predicated on a full theory of dipole-exchange spin wave scattering from interesting magnetic and nonmagnetic target materials in the thin film geometry particular to our experiment, which we have also developed.

(1.) T. X. Zhou et al., arXiv:2004.07763.