Wednesday, June 17, 2009

Room Temperature Superconductors One Step Closer

We are one step closer to room temperature superconductors.

Menlo Park, Calif.—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.
Pretty darn exciting. It all depends on something called topological insulation. The article gives some details on how that works. Which gets a bit heavy on the physics. I'm going to skip that here. However, if you have heard of the Pauli exclusion principle it is worth a read.

There are some limitations. For now.
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."
Bismuth Telluride is a semiconductor that is currently used for solid state refrigerators. It is also used to generate electricity from small temperature differences. That means the semiconductor industry has more than a little experience in fabricating the material.

If the lab boys have developed a repeatable formula it is possible we might see useful devices using this superconducting property in as little as three years. One use of such properties might be to make a super low noise microwave filter that doesn't require cooling to Liquid Nitrogen temperatures (77° Kelvin). That could be very helpful.

I will be keeping an eye on this one.

If "normal" superconductivity interests you this book is a good place to start:
Introduction to Superconductivity

And if you are a little further along and contemplate building a fusion reactor in your garage, this book could help:
Case Studies in Superconducting Magnets: Design and Operational Issues

Cross Posted at Classical Values

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