"Polar Kerr Effect from Time-Reversal Symmetry Breaking in the Heavy-Fermion Superconductor PrOs4Sb12"

E. M. Levenson-Falk: E. R. Schemm, Y. Aoki, M. B. Maple, and A. Kapitulnik; Physical Review Letters, 05/04/18.

Additional Authors: E. R. Schemm, Y. Aoki, M. B. Maple, and A. Kapitulnik

Abstract:

We present polar Kerr effect measurements of the filled skutterudite superconductor PrOs4Sb12. Simultaneous ac susceptibility measurements allow us to observe the superconducting transition under the influence of heating from the optical beam. A nonzero Kerr angle θK develops below the superconducting transition, saturating at ∼300  nrad at low temperatures. This result is repeated across several measurements of multiple samples. By extrapolating the measured θK(T) to zero optical power, we are able to show that the Kerr angle onset temperature in one set of measurements is consistent with the transition to the B phase at TC2. We discuss the possible explanations for this result and its impact on the understanding of multiphase and inhomogeneous superconductivity in PrOs4Sb12.