Researchers at Virginia Commonwealth University and the University of California, Los Angeles have made an important advance that could lead to more energy efficient magnetic memory storage components for computers and other devices.
Magnets are widely used for computer memory because their "up" or "down" polarity -- the magnetic state -- can be "flipped" to write or encode data and store information. Magnetic memory is nonvolatile, so information can be stored on devices without refreshing. However, magnetic memory also requires a lot of energy.
A recently discovered magnetic state called the skyrmion, which is neither "up" nor "down" but flower-shaped, offers a solution. Manipulating the skyrmion state allows for much more efficient, robust data storage for conventional computers and wireless smart devices.
"Our finding demonstrates the possibility of controlling skyrmion states using electric fields, which could ultimately lead to more compact, energy efficient nanomagnetic devices," said Dhritiman Bhattacharya, a doctoral candidate at the VCU College of Engineering and the lead author of the paper, "Creation and annihilation of non-volatile fixed magnetic skyrmions using voltage control of magnetic anisotropy."
The paper published in the June 29 issue of the journal Nature Electronics.
Jayasimha Atulasimha, Ph.D., Qimonda Professor in the VCU Department of Mechanical and Nuclear Engineering, is Bhattachayra's dissertation adviser and corresponding author of the paper. The finding outlined in the paper is "a steppingstone toward ultimately developing commercially viable magnetic memory based on this paradigm," Atulasimha said.
In 2016 and 2018, the VCU researchers showed that using an intermediate skyrmion state to force precise magnetic transitions between the "up" and "down" state could reduce errors in writing information to memory, making devices more robust to material defects and thermal noise. They hold a patent on this idea. The new proof-of-concept experiment presented in Nature Electronics is the first step toward making such a device.
The research is funded by the National Science Foundation, the U.S. Department of Defense, the U.S. Department of Energy, VCU, UCLA and VCU's C. Kenneth and Dianne Harris Wright Virginia Microelectronics Center.
The paper was authored by Bhattacharya, Atulasimha and UCLA researchers Seyed Armin Razavi; Hao Wu, Ph.D.; Bingqian Dai; and Kang L. Wang, Ph.D.