Final Report Summary - 3SPIN (Three Dimensional Spintronics)
Most of the research during the last 20 years in nanotechnology has concerned 2-dimensional systems, i.e. devices which are complex and controlled in the in-plane direction, but which have little complexity or functionality in the vertical direction. This project has investigated a new class of magnetic nanosystem in which complex 3-dimensional nanostructures are formed, with the intention of creating a host environment for topological solitons. Topological solitons are a type of frustration which can be designed into magnetic systems (analogous to Mobius Strips in twisted paper loops). These solitons have the potential to carry and process digital information and so are potentially important as memories and logic devices. The project has studied the basic physics of a wide range of solitons, both theoretically and experimentally. The project succeeded in creating a multilayer device in which multiple solitons could be injected, propagated and then detected, as a forerunner to a 3-dimensional data storage device. Unexpectedly, the project found that one of the best ways to use such nanostructures is in biomedical applications, since they allow the key problem of agglomeration to be solved. Agglomeration is the process by which magnetic nanoparticles in liquid attract each other through magnetic forces and stick together in a large clump. This usually destroys their ability to function correctly and so finding methods to prevent or limit agglomeration is an important problem. The project found that controlling toplogical solitons automatically controls agglomeration. This allowed a new type of magnetic liquid containing large numbers of 3-dimensional nanostructures to be made which has the remarkable property of not agglomerating while also retaining high levels of functionality. Future studies are planned to use these nanostructures in cancer therapy.