Researchers develop a magnetic nano-oscillator driven by pure spin current

(Nanowerk News) Data transmission with unprecedented high speed and electronic miniature components  these are visions of the future for scientists in the field of "Spintronics". Physicists of Münster University have taken a small step on the long way towards realizing these aims. They have developed a new source of electromagnetic radiation in the microwave frequency range. Such electromagnetic radiation is usually used for radio broadcasting and mobile phones.

The new radiation source no longer requires electrical charge transfer, but is driven by magnetic spin current. Due to its extremely small size (less than a millionth of a millimetre) and its easily shifted frequency range, such components could, for example, be used for miniature mobile phones in the future. Since there is no electric current flowing through the source of radiation, problems such as overheating and material degradation, which otherwise may occur in electrical devices, are no longer relevant.

The study, in which scientists from the USA were also involved, was published in the renowned scientific journal Nature Materials ("Magnetic nano-oscillator driven by pure spin current").

Electron spin is a quantum-mechanical quantity which describes the "magnetic moment" of electrons, i.e. a kind of rotation with a corresponding angular momentum. While electric currents are used in everyday electronic devices, spin currents form the basis for Spintronics. In a spintronic system, spin currents facilitate fast transfer, processing and storage of data. Thus, according to the scientists' vision, the quantum computer, which will surpass today's most powerful supercomputers by far, could one day become a reality.

The widespread application of spin currents is a dream of the future. However, scientists have already experimented with pure spin currents in order to suppress electronic noise caused by thermal fluctuations in magnetic nanocomponents, or to amplify propagating magnetization waves. The team from Münster is the first to have created a generator emitting electromagnetic waves independently by spin currents.