Observation of broken time-reversal symmetry in the heavy-fermion superconductor UPt 3

Abstract

Optically probed superconductor The exotic superconductor UPt 3 has two superconducting phases that appear at different temperatures, but their nature remains unclear. Schemm et al. shone circularly polarized light on a crystal of UPt 3 and studied its reflection (see the Perspective by van der Marel and Sawatzky). In the low-temperature phase, the pairs of electrons that make the material superconducting have a handedness to them. The finding narrows down the possible descriptions of the electron-pair wave function. Science , this issue p. 190 ; see also p. 138