"Local observation of linear-T superfluid density and anomalous vortex dynamics in U Ru2Si2"

Yusuke Iguchi: Irene P. Zhang, Eric D. Bauer, Filip Ronning, John R. Kirtley,and Kathryn A. Moler; Physical Review B, 06/07/21.

Additional Authors: Irene P. Zhang, Eric D. Bauer, Filip Ronning, John R. Kirtley,and Kathryn A. Moler

Abstract:

The heavy fermion superconductor U Ru2Si2 is a candidate for chiral, time-reversal symmetry-breaking superconductivity with a nodal gap structure. Here, we microscopically visualized superconductivity and spatially inhomogeneous ferromagnetism in U Ru2Si2 . We observed linear-T superfluid density, consistent with d -wave pairing symmetries including chiral d wave, but did not observe the spontaneous magnetization expected for chiral d wave. Local vortex pinning potentials had either four- or twofold rotational symmetries with various orientations at different locations. Taken together, these data support a nodal gap structure in U Ru2Si2 and suggest that chirality either is not present or does not lead to detectable spontaneous magnetization.