A new ultrafast control scheme of ferromagnet for energy-efficient data storage

Date:
October 16, 2020
Source:
Tohoku University
Summary:
Using a single laser pulse that did not switch the ferrimagnetic
layer, researchers demonstrated a much faster and less energy
consuming switching of the ferromagnet.



FULL STORY ==========================================================================
The digital data generated around the world every year is now counted in zettabytes, or trillions of billions of bytes -- equivalent to delivering
data for hundreds of millions of books every second. The amount of data generated continues to grow. If existing technologies remained constant,
all the current global electricity consumption would be devoted to data
storage by 2040.


========================================================================== Researchers at the Universite' 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.


========================================================================== Story Source: Materials provided by Tohoku_University. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Quentin Remy, Junta Igarashi, Satoshi Iihama, Gre'gory Malinowski,
Michel
Hehn, Jon Gorchon, Julius Hohlfeld, Shunsuke Fukami, Hideo
Ohno, Ste'phane 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 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201016112905.htm

--- up 7 weeks, 4 days, 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)