New Exotic Material Could Revolutionize Electronics

[Gawdzilla Sama]

New Exotic Material Could Revolutionize Electronics

ScienceDaily (June 16, 2009) — Move over, silicon—it may be time to give the Valley a new name. Physicists at the Department of Energy's (DOE) SLAC National Accelerator Laboratory and Stanford University have confirmed the existence of a type of material that could one day provide dramatically faster, more efficient computer chips.

Recently-predicted and much-sought, the material allows electrons on its surface to travel with no loss of energy at room temperatures and can be fabricated using existing semiconductor technologies. Such material could provide a leap in microchip speeds, and even become the bedrock of an entirely new kind of computing industry based on spintronics, the next evolution of electronics.

Physicists Yulin Chen, Zhi-Xun Shen and their colleagues tested the behavior of electrons in the compound bismuth telluride. The results, published online June 11 in Science Express, show a clear signature of what is called a topological insulator, a material that enables the free flow of electrons across its surface with no loss of energy.

The discovery was the result of teamwork between theoretical and experimental physicists at the Stanford Institute for Materials & Energy Science, a joint SLAC-Stanford institute. In recent months, SIMES theorist Shoucheng Zhang and colleagues predicted that several bismuth and antimony compounds would act as topological insulators at room-temperature. The new paper confirms that prediction in bismuth telluride. "The working style of SIMES is perfect," Chen said. "Theorists, experimentalists, and sample growers can collaborate in a broad sense."

The experimenters examined bismuth telluride samples using X-rays from the Stanford Synchrotron Radiation Lightsource at SLAC and the Advanced Light Source at Lawrence Berkeley National Laboratory. When Chen and his colleagues investigated the electrons' behavior, they saw the clear signature of a topological insulator. Not only that, the group discovered that the reality of bismuth telluride was even better than theory.

"The theorists were very close," Chen said, "but there was a quantitative difference." The experiments showed that bismuth telluride could tolerate even higher temperatures than theorists had predicted. "This means that the material is closer to application than we thought," Chen said.

This magic is possible thanks to surprisingly well-behaved electrons. The quantum spin of each electron is aligned with the electron's motion—a phenomenon called the quantum spin Hall effect. This alignment is a key component in creating spintronics devices, new kinds of devices that go beyond standard electronics. "When you hit something, there's usually scattering, some possibility of bouncing back," explained theorist Xiaoliang Qi. "But the quantum spin Hall effect means that you can't reflect to exactly the reverse path." As a dramatic consequence, electrons flow without resistance. Put a voltage on a topological insulator, and this special spin current will flow without heating the material or dissipating.

Topological insulators aren't conventional superconductors nor fodder for super-efficient power lines, as they can only carry small currents, but they could pave the way for a paradigm shift in microchip development. "This could lead to new applications of spintronics, or using the electron spin to carry information," Qi said. "Whether or not it can build better wires, I'm optimistic it can lead to new devices, transistors, and spintronics devices."

Fortunately for real-world applications, bismuth telluride is fairly simple to grow and work with. Chen said, "It's a three-dimensional material, so it's easy to fabricate with the current mature semiconductor technology. It's also easy to dope—you can tune the properties relatively easily."

"This is already a very exciting thing," he said, adding that the material "could let us make a device with new operating principles."

The high quality bismuth telluride samples were grown at SIMES by James Analytis, Ian Fisher and colleagues.

SIMES, the Stanford Synchrotron Radiation Lightsource at SLAC, and the Advanced Light Source at Lawrence Berkeley National Laboratory are supported by the Office of Basic Energy Sciences within the DOE Office of Science.

Journal reference:

1. Chen et al. Experimental Realization of a Three-Dimensional Topological Insulator, Bi2Te3. Science, 2009; DOI: 10.1126/science.1173034

Adapted from materials provided by DOE/SLAC National Accelerator Laboratory.

[Clinton Huxley]

I was sad when we moved from brass to bakelite but I suppose progress cannot be stopped.

[Gawdzilla Sama]

I was sad when we moved from brass to bakelite but I suppose progress cannot be stopped.

Don't worry. In a few decades the Industrial Revolution will be over.

[Clinton Huxley]

I was sad when we moved from brass to bakelite but I suppose progress cannot be stopped.

Don't worry. In a few decades the Industrial Revolution will be over.

Ended in the UK with Margaret Thatcher (boo, hiss etc).

[Gawdzilla Sama]

I was sad when we moved from brass to bakelite but I suppose progress cannot be stopped.

Don't worry. In a few decades the Industrial Revolution will be over.

Ended in the UK with Margaret Thatcher (boo, hiss etc).

I will never forgive James Watt.

[Clinton Huxley]

This is technology a man can understand, none of your electrolls or quantums or any of that nonsense:-

[Gawdzilla Sama]

This is technology a man can understand, none of your electrolls or quantums or any of that nonsense:-

http://www.londongrs.com/Watt/steam_engine.jpg

Nothing like a good piece of equipment built with hand-made nuts and bolts.

[ScholasticSpastic]

Put a voltage on a topological insulator, and this special spin current will flow without heating the material or dissipating.

Unimaginably increased energy efficiency, significantly reduced resistance/heat issues, probably significantly faster processing capabilities. I am very excited to see what the new generation of computers will look like!

[AshtonBlack]

Put a voltage on a topological insulator, and this special spin current will flow without heating the material or dissipating.

Unimaginably increased energy efficiency, significantly reduced resistance/heat issues, probably significantly faster processing capabilities. I am very excited to see what the new generation of computers will look like!

I bet microsoft could still make a version of windows that takes 10mins to boot up though!

[Xamonas Chegwé]

Put a voltage on a topological insulator, and this special spin current will flow without heating the material or dissipating.

Unimaginably increased energy efficiency, significantly reduced resistance/heat issues, probably significantly faster processing capabilities. I am very excited to see what the new generation of computers will look like!

I bet microsoft could still make a version of windows that takes 10mins to boot up though!

Gates' Law: Microsoft will expand to fill any given hardware / software capabilities and still require just a little more memory / processor speed / disk space / dilithium crystals than your current machine possesses.