Jun 2 2005
In conventional electronics, information is represented by the presence or absence of electrons. However, in the new field of spintronics, it is the electron spin (“up” or “down”) which encodes information. The single most critical problem in hybrid spintronic devices is the efficient transfer of spin between the ferromagnetic region (the spin injector) and the semiconductor region (where spins are controlled and manipulated to give the device functionality). It has now been well established that to overcome this problem a high resistance interface needs to be achieved between metal and semiconductor. The aim of this project is to engineer this interface to optimise spin injection and detection efficiencies.
The work builds on previous research at Surrey on electron spins in narrow bandgap semiconductors. These offer wide range of lattice matched materials that can be used to engineer the barrier layers, compared to the more conventional GaAs material. Other advantages are their much greater potential to manipulate the spin while traversing the semiconductor and their higher mobilities.
This research is part of a £1.1M project in collaboration with Imperial College London and Cambridge University, who will produce the spintronic devices. At Surrey, the electron spins will be optically probed after injection from the ferromagnet.
Professor Ben Murdin said "Spintronic devices incorporating semiconductors offer ways to keep up with Moore's Law of increasing computing power, to transmit unbreakable codes and to compute previously uncomputable problems. We think that with this project we have a good chance to develop the first spintronic transistor switch, and make a major leap forward in this area."
Materials Engineering To Optimise The Spin Dependent Transport Between Ferromagnetic Metals and Narrow Gap Semiconductors, B. N. Murdin and O. Hess (EPSRC EP/C511999/1, start date 1st April 2005, grant value £221,474)
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