Scanning tunneling microscopy (STM) measurements have been extensively performed on the easily cleavable (011) surface of ${\mathrm{UTe}}_2$, using both normal-metal and superconducting tips. Motivated by these experiments, we theoretically investigate the topological surface states on the (011) surface of ${\mathrm{UTe}}_2$. We find that a two-dimensional nearly flat band emerges in the $B_{3u}$ state, giving rise to a pronounced zero-energy peak in the surface density of states. This flat band is supported by two key mechanisms: (i) nontrivial Berry phases defined at multiple momenta give rise to low-energy in-gap states, and (ii) weak spin conservation allows the gap function to acquire phase winding. Furthermore, to investigate the relation between the zero-bias peak observed in recent STM experiments with a superconducting tip and the topological surface states, we calculate the nonequilibrium dc tunneling current in a junction between an $s$-wave superconductor and the (011) surface of ${\mathrm{UTe}}_2$. Our results provide crucial insights into the superconducting pairing symmetry realized in ${\mathrm{UTe}}_2$.

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• Andreev bound states
• Josephson effect
• Spin-triplet pairing
• Topological superconductors
• Heavy-fermion systems
• Superconductivity
• Bogoliubov-de Gennes equations
• Nonequilibrium Green's function
• Scanning tunneling microscopy
• Scanning tunneling spectroscopy