Jekyll-and-Hyde superconductor points to self-correcting quantum computers

A newly observed material – at once both a superconductor and a metal – could be destined for a stunning career in quantum computing, according to scientists at Princeton.

M. Zahid Hasan, associate professor of physics at Princeton, says that one of the most exciting uses for the material, known as a topological superconductor, would be in a quantum computer. It would allow the machine to spot and account for errors in a calculation, even while that same calculation was running.

But to do this, they have to find a particle that was predicted 70 years ago, and has yet to be observed. Hasan suggests that the dual nature of the topological superconductor, with its internal superconducting crystal structure, and metallic exterior, makes it a perfect “nursery” for the elusive Majorana fermion.

From the announcement: "These highly unusual superconductors are the most ideal nurseries to create and manipulate Majorana fermions, which could be used to do quantum computing in a fault-resistant way," said L. Andrew Wray, the first author of the paper, who received his doctoral degree from Princeton in 2010. "And because the particles would exist on a superconductor, it could be possible to manipulate them in low power-consumption devices that are not only 'green,' but also immune to the overheating problems that befall current silicon-based electronics."

But don’t hold your breath. Even the scientists think this one is several decades of development off, so graphene looks likely to keep its wünderkind reputation for some time to come.

The work is published in the November 1 issue of Nature, Physics. There is much (much) more information on the Princeton site, here.