A research team from the UCLA Henry Samueli School of Engineering and Applied Science is using electron spin to cut the power consumption of logic devices dramatically.
The team uses multiferroic materials that combine ferroelectric and magnetic properties to reduce the amount of power consumed by a factor of 1,000. To do this, the researchers generate a cascading wave in the spin of electrons in the material -- a process called a spin wave bus.
"Spin waves open an opportunity to realize fundamentally new ways of computing while solving some of the key challenges faced by scaling of conventional semiconductor technology, potentially creating a new paradigm of spin-based electronics," principal investigator Kang L. Wang, UCLA's Raytheon Professor of Electrical Engineering and director of the Western Institute of Nanoelectronics (WIN), said in a press release.
Spin-based devices are being researched around the world, but this is the first time one has been controlled with voltage.
A picture of spin wave devices showing magneto-electric cells used for voltage-controlled spin wave generation in the spin wave bus material (yellow stripe). The yellow stripe is about four micrometers in diameter.
(Source: UCLA Henry Samueli School of Engineering and Applied Science)
The multiferroic element consists of a magnetostrictive nickel film and a piezoelectric perovskite substrate. Applying an AC voltage to the piezoelectric crystal creates an oscillating electric field, which produces an alternating strain-induced magnetic anisotropy in the magnetostrictive layer. This drives spin waves along a 5 μm wide Ni/NiFe ferroelectric waveguide. The voltage-driven spin wave excitation could be used for low-dissipation spin wave-based logic and memory elements.
"Electrical control of magnetism without involving charge currents is a fast-growing area of interest in magnetics research," Pedram Khalili, a UCLA assistant adjunct professor of electrical engineering, said in the release. "It can have major implications for future information processing and data-storage devices, and our recent results are exciting in that context."
The researchers have published paper on their work in the journal Applied Physics Letters. They applied this technology in a similar way to computer memory by developing a magnetoresistive MeRAM in 2012. The research is funded by the Defense Advanced Research Projects Agency's Non-Volatile Logic program and by the Nanoelectronics Research Initiative through the WIN.