IBM Scientists "Waltz" Closer to Using Spintronics in Computing

Researchers from IBM Research and the university ETH, both based in Zurich have revealed their first ever direct mapping of information of a persistent spin helix in a semiconductor with the aim of using electron spins for storing, transporting and processing information.

Till date, whether or not electron spins possessed the capability to preserve the encoded information long enough before rotating remained a mystery. But the latest discovery shows that synchronizing electrons extends the spin lifetime of the electron by 30 times to 1.1 nanoseconds -- the same time it takes for an existing 1 GHz processor to cycle.

This new technique is limited as the semiconductor dimensions continue to shrink to the point where the flow of electrons can no longer be controlled. Spintronics could overcome this approaching gridlock by harnessing the spin of electrons instead of their charge.

This new understanding in spintronics not only gives scientists unprecedented control over the magnetic movements inside devices but also opens new possibilities for creating more energy efficient electronics.

The concept of locking the spin rotation was originally proposed in theory back in 2003 and since that time some experiments have even found indications of such locking, but until now it had never been directly observed.

IBM scientists imaged the synchronous 'waltz' of the electron spins by using a time-resolved scanning microscope technique.  The semiconductor material called gallium arsenide (GaAs) was produced by scientists at ETH Zurich who are known as world-experts in growing ultra-clean and atomically precise semiconductor structures. GaAs is a III/V semiconductor commonly used in the manufacture of devices such as integrated circuits, infrared light-emitting diodes and highly efficient solar cells.

The scientific paper entitled "Direct mapping of the formation of a persistent spin helix" by M.P. Walser, C. Reichl, W. Wegscheider and G. Salis was published online in Nature Physics,