Origin of high-energy tunneling resonances

Determine the origin of the additional tunneling-resonance peaks observed above the superconducting gap in stoichiometric FeTe and establish their relationship to superconductivity.

Background

The large-scale tunneling spectrum contains additional resonance peaks at energies above the superconducting gap. These peaks disappear at temperatures above the superconducting transition temperature, suggesting a possible connection to superconductivity.

Their microscopic origin and whether they represent superconducting, electronic, or extrinsic features are not resolved by the reported measurements.

References

Additional resonance peaks appear at energies above the superconducting gap and disappear at temperatures exceeding $T_c$ . The origin of these peaks and their relation to superconductivity are unclear.

— Signatures of nodal superconductivity in stoichiometric FeTe  (2609.08116 - Li et al., 8 Sep 2026) in Supplementary Information, Section “Large-scale tunneling spectrum in stoichiometric FeTe”, Fig. S16 caption