Spintronic Devices for Integrated Logic Circuits

In this proposal, we aim to develop four key spintronic devices in collaboration with Tohoku University in Japan and Technical University of Kaiserslautern in Germany as counterparts in a Core-to-Core Programme organised by the Japan Society for the Promotion of Science. We intend to investigate a spin transistor with an optical gate, an all Heusler alloy MRAM cell, spin-transfer torque induced by the spin See-beck effect and design a prototype logic circuit. Based on our ex-pertise, we anticipate to achieve three major milestones for next-generation integrated logic circuits: (i) instant power-on, (ii) low power consumption and (iii) less Joule heating. Each of these device concepts has the potential to be a component of an integrated spintronic logic and storage device. In addition to the technical activities this project will support an ambitious programme of exchange through the JSPS Core-to-Core Programme. We are committed to 9 exchanges per year giving a total of 45 exchanges to Germany but principally Japan over the 5 year period. This will be the largest programme of exchange in the field of magnetism ever undertaken from the UK.

The work in this project consists of 3 linked topics each of which has the potential to make significant economic impact if successful. The projects on MRAM elements and the spin transistor are more fundamental aspects of research but each is focussed on the necessary development of highly advanced materials for spintronic devices to become a reality. Hence it is research of a fundamental underpinning nature for applications. If those projects are successful the economic impact on a 5 to 10 year timescale could be significant via royalties and further industrial collaboration. Not included in this proposal but under separate arrangements a project related to a Heusler alloy read head has been funded by Seagate Technology N. Ireland as a PhD CASE Award.
The project on MRAM elements is fundamental underpinning science. However technological development is just beginning in the industrial sector. The announcement by Intel of their intention to commercialise STT-MRAM in the next three years means that there is an enormous effort in industry and academia in MRAM technology. If improved spin polarisation could be achieved using Heusler alloys, a step change in SNR in devices would result. This technology is probably five years from implementation but this project could be an important stepping stone towards commercialisation.
Given the state of the science and technology of spintronics direct and immediate commercial impact of the proposed projects is not expected. However the underpinning of the nature of the science which we wish to undertake is of clear importance as the basic research begins to evolve into device applications. Our connections to Seagate Technology, Seagate Media Research, Toshiba and Hitachi Cambridge places us in a strong position and gives us insights into research areas which are of importance for future technologies.
The invitation from JSPS to apply for this Core-to-Core project will also make this project have a very high impact in both academic and industrial fields. It is the policy of JSPS only to stimulate these projects on a "best with best" basis. Their selection of our group for this invitation is therefore highly prestigious for the UK community as a whole. We already have strong links to Tohoku University with Prof Hirohata holding a Visiting Professorship in that university and the long established connections to Prof O'Grady mean that the collaboration is already established. The University of York has a formal cooperation agreement with Tohoku University and a number of exchanges have taken place both under our previous EPSRC/JST grant in collaboration with Prof Ohno and also via other funding such as JSPS Fellowships. It is this close link to Tohoku that has led to the highly successful York-Tohoku Symposia on Magnetism and Spintronics the last two of which have attracted over 100 participants.
Prof O'Grady has long collaborated with Prof Hillebrands of Kaiserslautern University. They were the principals in an EU Training Network known as NEXBIAS some years ago but have worked together continuously through the IEEE Magnetics Society and the Editorial Board of J.Phys.D. A collaboration with Prof Hillebrands and via him to the rest of the spintronics community in Germany will make a significant impact on the UK community in this field via the open symposia that we will organise.