Researchers at the Université de Lorraine in France and Tohoku University reported on an innovative technology that leads to a drastic reduction in energy for data storage.

The established technology utilizes an ultrafast laser pulse whose duration is as short as 30 femto seconds -- equal to 0.0000000000000003 seconds. The laser pulse is applied to a heterostructure consisting of ferrimagnetic GdFeCo, nonmagnetic Cu and ferromagnetic Co/Pt layers.

"Previous research, conducted by a subset of the current research group, observed magnetic switching of the ferromagnetic layer after the ferrimagnetic layer had been switched." This time, the researchers uncovered the mechanism accounting for this peculiar phenomena and found that a flow of electron spin, referred to as a spin current, accompanying the switching of ferrimagnetic GeFeCo plays a crucial role in inducing the switching of ferromagnetic Co/Pt.

Based on this insight, they demonstrated a much faster and less energy consuming switching of the ferromagnet. This was driven by a single laser pulse without a switching of the ferrimagnetic layer. "This is very good news for future data-storage applications as this technology can provide an efficient scheme to write digital information to a magnetic medium, which is currently based on a magnetic-field-induced switching," says Shunsuke Fukami, co-author of the study.

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Materials provided by Tohoku University. Note: Content may be edited for style and length.

Journal Reference:

1. Quentin Remy, Junta Igarashi, Satoshi Iihama, Grégory Malinowski, Michel Hehn, Jon Gorchon, Julius Hohlfeld, Shunsuke Fukami, Hideo Ohno, Stéphane Mangin. Energy Efficient Control of Ultrafast Spin Current to Induce Single Femtosecond Pulse Switching of a Ferromagnet. Advanced Science, 2020; 2001996 DOI: 10.1002/advs.202001996