Probing p-wave superconductivity in UTe2 via point-contact junctions

Abstract

Uranium ditelluride (UTe 2 ) is the strongest contender to date for a p -wave superconductor in bulk form. Here we perform a spectroscopic study of the ambient pressure superconducting phase of UTe 2 , measuring conductance through point-contact junctions formed by metallic contacts on different crystalline facets down to 250 mK and up to 18 T. Fitting a range of qualitatively varying spectra with a Blonder-Tinkham-Klapwijk (BTK) model for p -wave pairing, we can extract gap amplitude and interface barrier strength for each junction. We find good agreement with the data for a dominant p y -wave gap function with amplitude 0.26 ± 0.06 meV. Our work provides spectroscopic evidence for a gap structure consistent with the proposed spin-triplet pairing in the superconducting state of UTe 2 .