Communications of the ACM
c Researchers Create All-Electric Spintronics
University of Cincinnati professor Philippe Debray (left), with Professor Marc Cahay (center) and graduate student Partha Pratim Das, says manipulating the orientation of an electron's spin with purely electrical means is "the holy grail of semiconductor
Credit: University of Cincinnati
University of Cincinnati (UC) researchers have developed a way to control an electron's spin orientation using only electrical means. Previous methods to develop spin transistors incorporated local ferromagnets into devices, but that significantly complicates designs. "A far better and practical way to manipulate the orientation of an electron's spin would be by using purely electrical means, like the switching on and off of an electrical voltage," says UC professor Philippe Debray. "This will be spintronics without ferromagnetism or all-electric spintronics, the holy grail of semiconductor spintronics."
Debray says the researchers used a quantum-point contact to generate strongly spin-polarized current. He says the key condition for the success of the experiment was that the potential confinement of the wire needed to be asymmetric, or the transverse opposite edges of the quantum point contact must be asymmetrical. "This was achieved by tuning the gate voltages," Debray says. "This asymmetry allows the electrons — thanks to relativistic effects — to interact with their surroundings via spin-orbit coupling and be polarized."
The researchers say the ability to control electrons' spin electronically has major implications for the future development of spintronic devices. The next step in the process would be to achieve the same results at a higher temperature using a different material.
From University of Cincinnati
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