UPt3 as a Topological Crystalline Superconductor

We investigate the topological aspect of the spin-triplet f-wave superconductor UPt3 through microscopic calculations of edge-and vortex-bound states based on the quasiclassical Eilenberger and Bogoliubov-de Gennes theories. It is shown that a gapless and linear dispersion exists at the edge of the ab-plane. This forms a Majorana valley, protected by the mirror chiral symmetry. We also demonstrate that, with increasing magnetic field, vortex-bound quasiparticles undergo a topological phase transition from topologically trivial states in the double-core vortex to zero-energy states in the normal-core vortex. As long as the d-vector is locked into the ab-plane, the mirror symmetry holds the Majorana property of the zero-energy states, and thus UPt3 preserves topological crystalline superconductivity that is robust against the crystal field and spin-orbit interaction.