Modelling of graphene-based spintronic devices

Spintronics is a form of electronics which relies on the measurement and control of the spin degree of freedom of electrons, as well as their charge. A promising, new candidate material for the realisation of spintronics devices is graphene, a single-atom thick sheet of carbon atoms, because it is a good conductor and spin relaxation is supposed to be very slow in it. By employing gate electrodes, it is easy to tune the carrier density of graphene from particle to hole channels. Moreover, it is possible to change the electrical and magnetic properties of graphene in various ways: by creating nanoribbons; coverage with adatoms; proximity to other materials; or by using few-layer graphene materials (bilayers/trilayers etc).Over the course of the next three years, we expect that there will be a concerted international effort by chemists, physicists and engineers to understand the underlying mechanisms of spintronics in graphene, to improve fabrication techniques of graphene and related materials including attempts to develop magnetic properties, and to develop spintronics devices in graphene. Oustanding issues include an understanding of the causes of spin relaxation in graphene; whether, with the apparent lack of magnetism and the weakness of spin-orbit coupling, it is possible to manipulate spins in graphene; whether, given the unusual band structure of graphene, it will be possible to realise spintronics devices with functionality unique to graphene. The aim of the proposed collaboration is to contribute to a resolution of these issues, by developing the theory of spin-orbit coupling and magnetic impurities in graphene, to predict their manifestation in experimental characterisation of graphene, and to model spin-polarised transport in graphene-based spintronic devices.

This research project shares the general objective of fundamental nanoscience, namely, to identify unconventional material properties and novel functionalities which provide the basis for medium-term applied research and long-term commercial applications in the electronics and information storage industry. In particular, graphene is the only new material with realistic potential for applications in electronics that has appeared since carbon nanotubes more than a decade ago. There is no guarantee that graphene will be the silicon of the future or even the basis of novel spintronic devices, still, it is quite clear that the potential of this material is worthy of investigation. The use of graphene may lead to spintronic devices with speed, versatility, low power consumption, small physical dimension, or new functionality (for example, by combining magnetic functionality with transistor operation within a single device). This may have implications in microelectronics, sensor applications, high-density information storage, bio-medicine, quantum computing, etc. We aim to disseminate our results to a large audience including specialists, such as the rapidly-expanding international community of scientists and technologists working on spintronics and graphene, and to a non-specialist general audience. Specifically, we intend to Develop and maintain a project website, including information about our aims, achievements, and publications. Publish the results of our research in internationally-respected journals (e.g. Nature Physics, Physical Review). Organise mini-conferences (two in Lancaster, one in Tokyo) during the course of the project. Attend international conferences and workshops in order to present talks and posters, and to contribute to Conference Proceedings. Disseminate to a broad audience by giving Summer School Lectures, writing Review and News and Views Articles, providing press interviews. Support public outreach activities: at Lancaster, the arrival of IOP Teaching Fellow Philip Furneaux in 2008/09 has stimulated Physics Department outreach activities with school visits and teacher days.