New physics finding may lead to non-electronic gadgets, scientists say
Physicists find a way to amplify 'spin current,' a significant step in
the world of spintronics. Earlier related research made it possible for
the solid-state drives found in iPhones and other newer gadgets.
In a new scientific paper, scientists in Germany and the United
Kingdom have come up with a new technique to amplify the "spin current"
of electrons - and that could pave the way for significant improvements
in consumer electronics, possibly including storage devices that no
require no electricity at all.
In an article published online in the journal Nature Materials on
Sunday, the team from the University of Cambridge and the University of
Münster outlined what may be the next step in "spintronics."
This new area physics research is being hailed as the successor of
conventional electronics, based on transistor and semiconductor
technology. In general, for over the last 50 years, the number of
transistors that can be put on an integrated circuit doubles
approximately every 18 to 24 months.
However, the number of transistors is now getting so large, on such a
small space, that it's beginning to hit its physical limits, and will
soon reach the size of individual atoms.
 Information transfer could be enhanced because electrons have an intrinsic 'spin'The neglected spin
Conventional electronics have been based on harnessing the charge of
electrons. When they move, they generate electric current, which can be
used to transfer information. But electrons can do more than just travel
in a linear direction - one quantum-mechanical characteristic is their
intrinsic spin. Just as an ice skater twirls, so too do electrons.
Spintronics makes use of both the intrinsic spin of the electron and
its fundamental electronic charge. In theory, scientists say that by
harnessing this electronic spin as a way to store data at high-speed and
low-power. Conceivably, that could make internal batteries, or even
booting up a device, completely unecessary.
The research teams worked on enhancing existing magneto-based spintronics.
Physicists already know that a magnetic field can manipulate the spin
of the electron, which in turn, will impact neighboring electrons,
causing them to also start spinning, generating a so-called spin wave.
The scientists observed that spin waves often interact - just like how
ocean waves collide with each other.
 Portable devices like the iPod were developed with the help of spin-based electronicsAccumulating spins
"We brought our spin waves into interaction and attempted to see what
happens", said Hidekazu Kurebayashi, a physicist the Microelectronics
Group at the Cavendish Laboratory at the University of Cambridge, in an
e-mail sent to Deutsche Welle. "We observed a significant enhancement of
the spin current generation."
One of the spin wave interactions, the researchers found, generates
spin current ten times more efficiently than using pre-interacting spin
waves. How to amplify spins even further, however, continues to be an
unsolved question - for now.
"In normal semiconductor electronics, amplification is possible using
an electric field to accumulate charges, e.g. FET (field effect
transistors)", Kurebayashi added, but "there is so far no way to
accumulate spins in solid state."
Other physicists say that they are intrigued by this new work.
"It's an important step forward in the field of metal- or
magneto-based spintronics", noted Wolfram Heimbrodt, a physics professor
at Marburg University, who was not part of the study.
Earlier discoveries in spintronics research in the 1980s paved the
way for solid-state memory chips, which are used today in smartphones,
tablet devices and an increasing number of laptops. With any luck,
scientists say, the current research in spintronics could have an
equally significant affect on the next generation of consumer
electronics.
"The challenge is now to build devices where the electron's spin is
combined with the semiconductor technology", Heimbrodt told Deutsche
Welle. "It may take another ten years at least before we find out how to
combine the electron's spin with the semiconductor technology in
electronic devices."
Author: Nina Haase
Editor: Cyrus Farivar
http://www.dw-world.de/dw/article/0,,15209635,00.html
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