Speaker
Description
The heavy-fermion compound UTe2 is a candidate for hosting intrinsic spin-triplet superconductivity. At present, however, the type of triplet Cooper pairing realized in UTe2 remains unknown, which calls for further experimental and theoretical investigations. Using a microscopic minimal model for the superconducting phases, we examine which imprints of the superconducting order parameter occur on the surface spectral function. Crystalline symmetries determine the properties of the topological surface states allowing to discriminate superconducting order parameters transforming differently under remaining symmetries of the surface.
From the perspective of the bulk superconductivity, it turns out that the relative direction of the d-vector that parametrizes the triplet order parameter can be detected in data from quasiparticle interference. We show that beyond the enhanced density of states close to the nodes, one is able to distinguish the allowed superconducting ground states B2u and B3u as proposed for UTe2.
Technical complications of these investigations are the body-centered orthorhombic structure allowing a number of pairing contributions leading to accidental nodes on the Fermi surface, the nature of the electronic states exhibiting strong spin orbit coupling and the fact that atomically flat surfaces suitable for scanning tunneling microscopy can only be achieved on a (0-11) cleaving plane.