One of the main research interests of the functional magnetism group is the magnetic properties of nanostructured materials and devices. We have an interest in magnetic nanostructured arrays that are usually called Artificial Spin Ice. We have recently developed a method of writing any magnetic pattern we choose into these magnetic arrays using a magnetic force microscope.1,2 The aim of this project will be to fabricate artificial spin Ice structures and to use the writing technique to explore the possibilities for two new types of computation. One of these, known as a neural network, is a massively parallel computation based on the collective response of the whole network. The other, known as magnonics3, relies on manipulating spin waves (magnons) within the structures. Ferromagnetic resonance, or FMR, is a standard tool used for probing spin waves and spin dynamics in ferromagnetic materials. FMR arises from the precessional motion of the magnetization of a ferromagnetic material in an external magnetic field.
[1] Testing and training the 'neural network' response from different starting configurations.
[2] Testing the FMR with different array geometry and starting configuration and optimising for magnonics.
1J.C. Gartside, D.M. Arroo, D.M. Burn, V.L. Bemmer, A. Moskalenko, L.F. Cohen and W.R. Branford, Realising the kagome ice ground state and thermally inaccessible states via topological defect-driven magnetic writing. Nature Nanotechnology: Accepted for publication (2017). (Preprint at https://arxiv.org/abs/1704.07439)
2J.C. Gartside, D.M. Burn, L.F. Cohen and W.R. Branford, A novel method for the injection and manipulation of magnetic charge states in nanostructures. Scientific Reports. 6: 32864 (2016).
3D. Grundler, Reconfigurable magnonics heats up. Nature Physics. 11: 438-441 (2015).