A team of Duke University and Weizmann Institute researchers report a keystone achievement in the spintronics field: the development of a conducting system that controls the spin of electrons and transmits a spin current over long distances, without the need for the ultra-cold temperatures required by typical spin-conductors.
In most current technologies, data is encoded as a zero or a one, depending on the number of electrons that reach a capacitor. With spintronics, data is also transferred according to the direction in which these electrons spin.
Electrons are like spinning tops. Spin-up electrons rotate clockwise, and spin-down electrons rotate counter-clockwise. Electrons with opposite spins can occupy the same volume, but electrons that spin in the same direction repel themselves, like magnets of the same polarity.
By controlling the way that electrons spin along a current, scientists can encode a new layer of information into an electric signal.
Rather than simply turning capacitors on and off in a binary fashion, spintronic devices could also send signals according to the electron’s spin, where spin-up may mean something different than spin-down.
Ordinary device currents are composed of equal numbers of spin-up and spin-down electrons. At room temperature, it is challenging to generate a current composed largely of a single spin. The spins flip around, collapse onto one another, drop out of line, and deform the signal like a bad game of telephone.
The team developed a strategy to build molecular conductors that keep the electrons in line, ensuring that all of them are spinning in harmony and propagating the direction of spin over long distances, allowing signals to be transmitted with high fidelity, at room temperature. (SciTechDaily)
The study has been published in Proceedings of the National Academy of Sciences.