Multiple superconducting phases and order-parameter evolution in pressurized UTe₂

The recently discovered heavy-fermion spin-triplet superconductor candidate UTe₂ provides a rich platform for unconventional pairing and topological phenomena. However, limited has been known about its superconducting order parameters and their evolution with control parameters, largely due to the lack of appropriate symmetry-sensitive detection methods. Here, we report comprehensive point-contact spectroscopy measurements of pressurized UTe₂ on the (0 0 1) surface. The observation of Andreev bound states strongly suggests the presence of a p_z component in the superconducting order parameters. Quantitative analysis based on an extended Blonder-Tinkham-Klapwijk model unveils the superconducting order parameters with a finite odd-k_z component (e.g., B_2u or B_3u) for both ambient and pressurized UTe₂. Remarkably, the multiple superconducting phases can be distinguished by a single parameter 〈Δ_z〉/〈Δ_x(y)〉, the relative weight between the p_z-wave and p_x(y)-wave pairings. These findings place stringent constraints on the pairing symmetry and provide essential spectroscopic signatures for distinguishing pressure-induced multiple superconducting phases in UTe₂.