Spintronics is a research area focusing on making computers smaller and faster. Moore’s Law states that the number of transistors on a chip doubles every 2 years. However as conventional chip fabrications techniques will eventually reach a physical limit scientists need to come up with new ways of fulfilling this law.
Conventional electronics rely on the movement and charge of electrons to carry out calculations or to store data. In Trinity College Dublin, scientists are trying to harness the magnetic spin of an electron, rather than it's charge, to carry information. Manipulating the spin expends much less energy than moving it from one place to another. The spin itself is manifested as detectable weak magnetic force called either ‘spin up’ or ‘spin down’.
A goal of spintronics is to develop a semiconductor that can manipulate an electron's magnetism. Semiconductors are used to manufacture microchips which are at the heart of many electronic devices. Scientists want to be able to control the electron and switch the ‘spins’ whatever way they want. To create a useful spintronic device the semiconductor must be magnetised and remain stable at room temperature. Researchers have proposed that the best way to create material like this is to incorporate a magnetic element into a traditional semiconductor such as silicon.
Professor Michael Coey’s research group in Trinity is investigating new magnetic semiconductors and transparent ferromagnetic metals, trying to understand their bizarre combinations of properties, and seeing how they may be applied in nanodevices. They are also developing novel magnetic sensor concepts and, together with INTEL researcher-in-residence Chris Murray, they are investigating spin-polarised currents in silicon, the workhorse of the semiconductor industry.
Chris Murray is working on one aspect of this project and he is researching materials for spintronics. He is looking at materials that might work with silicon and work at room temperature. Intel have spent billions around the world developing factories that can handle silicon (like Fab 24 in Leixlip).
It is still early days in the Spintronics world but in 5 years time this technology will be becoming more and more prevalent and scientist will have answered more and more questions. And you probably won’t be able to see your iPod it’ll be so small!