Pair wave function symmetry in UTe₂ from zero-energy surface state visualization

although nodal spin-triplet topological superconductivity appears probable in uranium ditelluride (UTe₂), its superconductive order parameter Δ_k remains unestablished. In theory, a distinctive identifier would be the existence of a superconductive topological surface band, which could facilitate zero-energy andreev tunneling to an s-wave superconductor and also distinguish a chiral from a nonchiral Δ_k through enhanced s-wave proximity. In this study, we used s-wave superconductive scan tips and detected intense zero-energy andreev conductance at the UTe₂ (0-11) termination surface. Imaging revealed subgap quasiparticle scattering interference signatures with a-axis orientation. The observed zero-energy andreev peak splitting with enhanced s-wave proximity signifies that Δ_k of UTe₂ is a nonchiral state: B₁u, B₂u, or B₃u.