Scanning probe lithography for spintronic and plasmonic nanodevices

To explore new phenomena in a material, it is often necessary to probe the physical properties (electrical, optical, magnetic and structural) on lengthscales inaccessible to bulk measurement. This is particularly important, for example, in magnetism and plasmonics research, where new resonant excitations, couplings and interactions emerge when thin multilayer films are patterned on the nanometre lengths. Probing the interaction between light, spin-polarised currents and magnetic order on such lengthscales offers new approaches to energy efficient data storage; next-generation computation, including bio-inspired neural networks; and near-field terahertz emitters.
While methods are commonplace for processing samples into nanoscale devices, further progress in such investigations requires techniques which selectively control film properties in new ways. In particular, while it is relatively easy to pattern a film into a specific shape on nanometre lengths, it is often difficult to separately alter its physical properties on a similar scale.
In this project we will explore the use of a novel fabrication technique, termed thermal scanning probe lithography, to tailor physical properties at the nanoscale. The project will develop a toolkit for the fabrication of high-quality nanoscale magnetic and optical nanodevices. By selectively tuning the properties - controlling shape, composition and interfaces - of arrays fabricated from multilayers of common magnetic and plasmonic materials, including Au, Co and NiFe, we will investigate the properties of complex nanostructured islands, elucidating the role of inter- and intra-island interactions on groundstate in magnetic and plasmonic arrays. Exploring the competition between magnetic energy terms at these lengthscales can lead to entirely unconventional magnetic states, which we will explore as we elucidate the physical phenomena underpinning the interaction between dynamic magnetic excitation, spin-polarised electrical currents and plasmonic response.