String Theory and Black Holes Show Possible Path to Practical Superconductors

The unit cell of high-temperature cuprate superconductor BSCCO-2212

The unit cell of high-temperature cuprate superconductor BSCCO-2212

Alasdair Wilkins writes on

A leading candidate for room temperature superconductors is the copper compound cuprate, but no one knew how cuprates facilitated superconductivity … until some brave souls looked inside a black hole and broke out the string theory to explain how they work.

Superconductors that can transmit massive amounts of electricity with zero resistance at room temperature are pretty much the holy grail of applied physics (with good reason), but we’re still a long way away from actually building one.

Indeed, even figuring out the theoretical underpinnings of a room temperature superconductor has proven tremendously difficult, although a team of MIT physicists may have found an unlikely — and brilliant — way to learn more about how they would work. But first, a little backstory.

Currently, there are two types of superconductors. One group is the low temperature superconductors, which can only work at temperatures near absolute zero and thus require gigantically impractical amounts of coolants. The other set is the high temperature superconductors, which still have to be kept more than a hundred degrees Celsius below zero. They require slightly less impractical but still pretty damn impractical amounts of coolants (that’s a technical term). Researchers focus on the second set to see if they can boost the working temperature another hundred or so degrees.

Cuprates are compounds that include copper anions, or copper atoms with more electrons than protons and, as a result, a negative charge. The physicists Georg Bednorz and Karl Müller discovered a cuprate compound, specifically lanthanum barium copper oxide, was a superconductor at the relatively high temperature of 135 degrees Celsius above absolute zero. They won a Nobel Prize for their efforts, and a bunch of other cuprate compounds have since been discovered that also have superconductivity properties…

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