Scanning probe lithography for spintronic and plasmonic nanodevices

为了探索材料中的新现象，通常需要在本体测量无法达到的长度尺度上探测其物理性质（电学、光学、磁性和结构）。这一点尤其重要，例如，在磁学和等离子体研究中，当多层薄膜在纳米长度上形成图案时，会出现新的共振激发、耦合和相互作用。在这种长度尺度上探测光、自旋极化电流和磁序之间的相互作用，为节能数据存储提供了新的途径；下一代计算，包括生物启发神经网络；以及近场太赫兹发射器。虽然将样品加工成纳米级器件的方法是常见的，但在这类研究中的进一步进展需要有选择地以新方法控制薄膜性质的技术。特别是，虽然在纳米长度上将薄膜图案化成特定的形状相对容易，但在类似的尺度上单独改变其物理性质通常是困难的。在这个项目中，我们将探索使用一种新的制造技术，称为热扫描探针光刻，在纳米尺度上定制物理特性。该项目将开发一个工具包，用于制造高质量的纳米级磁性和光学纳米器件。通过选择性地调整由常见磁性和等离子体材料（包括Au， Co和NiFe）多层制成的阵列的性质-控制形状，组成和界面，我们将研究复杂纳米结构岛屿的性质，阐明岛屿间和岛屿内相互作用对磁性和等离子体阵列基态的作用。在这些长度尺度上探索磁能项之间的竞争可以导致完全非常规的磁态，我们将在阐明支撑动态磁激发，自旋极化电流和等离子体响应之间相互作用的物理现象时进行探索。

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.