Physicists put a new spin on electrons

April 15, 2009

In the first demonstration of its kind, researchers at the University of British Columbia have controlled the spin of electrons using a ballistic technique--bouncing electrons through a microscopic channel of precisely constructed, two-dimensional layer of semiconductor.

It's the first time the intrinsic properties of a semiconductor—not external electric or magnetic fields-have been used to achieve the effect. The findings, published this week in Nature, could have implications for the development of so called 'spintronic' circuits: systems that use the directional spin of to store and process data.

"The need to use high-frequency external fields to control spin is one of the major stumbling blocks in using electrons for information processing, or in a spintronic circuit," notes Joshua Folk, principal investigator on the project and Canada Research Chair in the Physics of . "We show that the spin of electrons can be controlled without external fields, simply by designing the right circuit geometry and letting electrons move freely through it."

The new technique uses the natural interactions of the electrons within the semiconductor micro-channel to control their spin--a technique that is a major step, but not yet flexible enough for industrial applications, notes Folk, an Assistant Professor with Physics and Astronomy who came to UBC via the Massachusetts Institute of Technology.

Electronic systems that use the spin of an electron--a quantum mechanical property that comes in two varieties: up or down--would work similarly to today's , but be smaller and use less energy.

Presently, electrical charge alone is responsible for the logic functions in circuits. Power consumption by these circuits is the primary roadblock to faster, more powerful processors. A spintronic circuit has the potential to use less power by storing and manipulating a bit of information as electron .

Spintronic circuits may also be a viable avenue for building quantum information processing devices. The exponentially faster processing possible with such a device could have applications ranging from code breaking, to dramatically improved drug design, to simulations of complex processes in molecular systems.

Next steps by Folk and his team—working with colleagues at the Universität Regensburg in Germany—will include using new devices to gain more precise control over the alignment and trajectory of the electrons.

More information:

Source: University of British Columbia (news : web)

Explore further: Spintronic transistor is developed

Related Stories

Spintronic transistor is developed

October 23, 2005

Researcher Christian Schoenenberger and colleagues at the University of Basel, Switzerland, developed a carbon nanotube transistor, opening a promising avenue toward the introduction of spin-based devices into computer chips, ...

Spin-polarized electrons on demand

January 15, 2009

Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Different from electronics, where whole ...

Spin-polarized electrons on demand

January 21, 2009

Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Different from electronics, where whole ...

Recommended for you

A quantum of light for materials science

December 1, 2015

Computer simulations that predict the light-induced change in the physical and chemical properties of complex systems, molecules, nanostructures and solids usually ignore the quantum nature of light. Scientists of the Max-Planck ...

Quantum dots used to convert infrared light to visible light

December 1, 2015

(—A team of researchers at MIT has succeeded in creating a double film coating that is able to convert infrared light at modest intensities into visible light. In their paper published in the journal Nature Photonics, ...

Test racetrack dipole magnet produces record 16 tesla field

November 30, 2015

A new world record has been broken by the CERN magnet group when their racetrack test magnet produced a 16.2 tesla (16.2T) peak field – nearly twice that produced by the current LHC dipoles and the highest ever for a dipole ...

Turbulence in bacterial cultures

November 30, 2015

Turbulent flows surround us, from complex cloud formations to rapidly flowing rivers. Populations of motile bacteria in liquid media can also exhibit patterns of collective motion that resemble turbulent flows, provided the ...


Adjust slider to filter visible comments by rank

Display comments: newest first

4 / 5 (1) Apr 15, 2009
Interesting, but I'd like to hear about what properties/forces in the circuit interact with the electron spin. Is it simply that the spins of the electrons in the surrounding circuit are all lined up, like a magnet?

I guess I'll just have to read them there papers and find out. Gosh darn it!
not rated yet Apr 16, 2009
Rest easy! Until we can create a perfect vacuum we can never observe what happens in it! If we introduce "light" we destroy the vacuum!
not rated yet Apr 16, 2009
Also, by the way, did you know that the body's communications network is "spintronic"? Electrons "dance", "spin", and change velocity in neural and other systems to convey inteligence!
not rated yet Apr 21, 2009
It would be nice of them to explicitly mention what the mechanism behind the spin-flips is. My best guess (without having read the paper) is that it's the spin-orbit interaction... a momentum dependant magnetic field.

Would also be nice to know what material system they're using. Congrats to the writer of this article for missing 90% of the relevant scientific information.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.