Spin Symmetry...

Illustration of symmetry in the magnetic properties—or nuclear spins—of strontium atoms. JILA researchers observed that if two atoms have the same nuclear spin state (top), they interact weakly, and the interaction strength does not depend on which of the 10 possible nuclear spin states are involved. If the atoms have different nuclear spin states (bottom), they interact much more strongly, and, again, always with the same strength.
Credit: Ye and Rey groups and Steve Burrows/JILA

Just as diamonds with perfect symmetry may be unusually brilliant jewels, the quantum world has a symmetrical splendor of high scientific value.

Confirming this exotic quantum physics theory, JILA physicists led by theorist Ana Maria Rey and experimentalist Jun Ye have observed the first direct evidence of symmetry in the magnetic properties—or nuclear “spins”—of atoms. The advance could spin off practical benefits such as the ability to simulate and better understand exotic materials exhibiting phenomena such as superconductivity (electrical flow without resistance) and colossal magneto-resistance (drastic change in electrical flow in the presence of a magnetic field).

The JILA discovery, described in Science Express,* was made possible by the ultra-stable laser used to measure properties of the world’s most precise and stable atomic clock.** JILA is jointly operated by the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder.

“Spin symmetry has a very strong impact on materials science, as it can give rise to unexpected behaviors in quantum matter,” JILA/NIST Fellow Jun Ye says. “Because our clock is this good—really it’s the laser that’s this good—we can probe this interaction and its underlying symmetry, which is at a very small energy scale.”

NIST: JILA Team Finds First Direct Evidence of 'Spin Symmetry' In Atoms, Laura Ost