Shot-noise and differential conductance as signatures of putative topological superconductivity in FeSe${}_{0.45}$Te${}_{0.55}$

Abstract

We present a theory for the differential shot noise, $dS/dV$, as measured via shot-noise scanning tunneling spectroscopy, and the differential conductance, $dI/dV$, for tunneling into Majorana zero modes (MZMs) in the putative topological superconductor FeSe${}_{0.45}$Te${}_{0.55}$. We demonstrate that for tunneling into chiral Majorana edge modes near domain walls, as well as MZMs localized in vortex cores and at the end of defect lines, $dS/dV$ vanishes whenever $dI/dV$ reaches a quantized value proportional to the quantum of conductance. These results are independent of the particular orbital tunneling path, thus establishing a vanishing $dS/dV$ concomitant with a quantized $dI/dV$, as universal signatures for Majorana modes in two-dimensional topological superconductors, irrespective of the material's specific complex electronic bandstructure.

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Cited by in corpus (3)

• Single-electron charge transfer into putative Majorana and trivial modes in individual vortices
• Competing topological superconducting phases in FeSe${}_{0.45}$Te${}_{0.55}$
• Excess photon-assisted noise of Majorana and Andreev bound states