Physicists observe exotic state first proposed in helium-3, in an unconventional superconductor

A new fractional vortex state observed in an unconventional superconductor may offer the first glimpse of an exotic state of matter predicted theoretically for more than 30 years. In a paper published in the January 14 issue of Science, University of Illinois physicists, led by Raffi Budakian, describe their observations of a new fractional vortex state in strontium ruthenium oxide (SRO). Such states may provide the basis for a novel form of quantum computing in which quantum information is encoded in the topological properties of a physical system.

"We've been on the trail of a state of matter called a half-quantum vortex for more than three years," said Budakian. "First proposed in the 1970s to exist in superfluid helium-3, a half-quantum vortex can be thought of as a 'texture' that arises from the spin phase of the superconducting order parameter."