Scanning tunneling microscopy and spectroscopy offer real-space access to electronic states, but conventional metallic tips average out momentum-dependent information critical to unconventional superconductivity. We demonstrate momentum-selective STM using a systematically engineered zigzag graphene tip. Atomic-resolution imaging on Ag(111) and FeSe confirms the tip’s performance, while spectroscopy on Ag(111) identifies an electronic signature consistent with a zigzag edge state at the apex. Friedel oscillations measured with these tips further demonstrate momentum-selective tunneling between the quasi-one-dimensional zigzag edge state and the two-dimensional Ag(111) surface state.

We apply this method to FeSe, where the superconducting gap is highly anisotropic in momentum space. On pristine FeSe, the momentum-selective zigzag tip resolves distinct low-energy spectra: a shallow hard gap appears when the tip’s momentum window avoids the nodal region, while a nodal-like spectrum emerges when the window overlaps the gap node. Measurements across a FeSe twin boundary further validate the tip’s momentum selectivity by resolving two distinct superconducting gaps across the boundary with fixed tip selectivity. Given the simplicity and broad applicability of this technique, we anticipate that our vdW tips will serve as a valuable tool for studying low-dimensional condensed matter systems.