IBM engineers have discovered that electrons can dance, an ability that they believe can be harnessed to create smaller and more energy-efficient computing devices.
If this idea can be practically deployed in products — and it's a big if, because at this point, the technique requires very low temperatures — it could lead to more powerful desktop computers, tablets and smartphones that consume less electricity. This in turn could lead to energy cost savings for banks and more productive portable devices for their employees and customers.
The IBM staff and scientists at European university ETH Zurich have observed that electron spins move tens of micrometers in a semiconductor channel, with their orientations synchronously rotating along the path similar to that of a couple dancing a waltz. This synchronization extends the spin lifetime of the electron by 30 times to 1.1 nanoseconds, the same time it takes for a 1 GHz processor to cycle.
Dr. Gian Salis of the Physics of Nanoscale Systems research group at IBM Research-Zurich explains: "If all couples start with the women facing north, after a while the rotating pairs are oriented in different directions. We can now lock the rotation speed of the dancers to the direction they move. This results in a perfect choreography where all the women in a certain area face the same direction. This control and ability to manipulate and observe the spin is an important step in the development of spin-based transistors that are electrically programmable."
Today's computing technology encodes and processes data by the electrical charge of electrons. However, this 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 surmount this approaching impasse by harnessing the spin of electrons instead of their charge.
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.
Transferring spin electronics from the laboratory to the market still remains a major challenge. Spintronics research takes place at very low temperatures at which electron spins interact minimally with the environment. In the case of this particular research IBM scientists worked at 40 Kelvin (-233 C, -387 F).
This work was financially supported by the Swiss National Science Foundation through the National Center of Competence in Research.