Shot-noise and differential conductance as signatures of putative topological superconductivity in FeSe_0.45Te_0.55

I 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_0.45Te_0.55. I show 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 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 band structure.