A robust zero-bias conductance peak in putative p-wave superconductors is often regarded as the primary signature of a Majorana zero mode. Yet similar features can also arise from trivial bound states. This ambiguity has limited the reliability of conventional spectroscopy as a diagnostic tool, raising a long-standing problem of how to detect such impostors. Here, we address this issue with an alternative approach, atomic-scale shot-noise spectroscopy, that goes beyond conductance measurements. Through a detailed investigation of multiple defect-bound zero-bias states in the widely studied superconductor Fe(Se,Te), we observe that differential conductance can exhibit an apparently `robust' zero-bias peak. However, shot-noise measurements consistently reveal the fingerprint of the individual particle- and hole character hidden in the tunnelling conductance, unambiguously exposing the trivial nature of the zero-bias peak. Our results establish shot-noise spectroscopy as a decisive diagnostic for ruling out false Majorana signatures in atomic-scale experiments.
Cite
@article{arxiv.2604.26002,
title = {Exposing impostor Majorana zero modes through atomic-scale shot-noise},
author = {A. Maiti and G. D. Gu and F. Massee},
journal= {arXiv preprint arXiv:2604.26002},
year = {2026}
}