# Nearly quantized conductance plateau of vortex zero mode in an iron-based superconductor

## TL;DR

This study demonstrates nearly quantized conductance plateaus in vortex zero modes of FeTe0.55Se0.45, providing strong evidence for Majorana zero modes and highlighting their potential for topological quantum computing.

## Contribution

It reports the first observation of conductance plateaus near 2e2/h in vortex zero modes of an iron-based superconductor, supporting the existence of Majorana zero modes.

## Key findings

- Conductance plateaus close to 2e2/h observed in vortex zero modes.
- No such plateaus observed in finite energy bound states.
- Supports Majorana zero modes in FeTe0.55Se0.45 superconductor.

## Abstract

Majorana zero-modes (MZMs) are spatially-localized zero-energy fractional quasiparticles with non-Abelian braiding statistics that hold a great promise for topological quantum computing. Due to its particle-antiparticle equivalence, an MZM exhibits robust resonant Andreev reflection and 2e2/h quantized conductance at low temperature. By utilizing variable-tunnel-coupled scanning tunneling spectroscopy, we study tunneling conductance of vortex bound states on FeTe0.55Se0.45 superconductors. We report observations of conductance plateaus as a function of tunnel coupling for zero-energy vortex bound states with values close to or even reaching the 2e2/h quantum conductance. In contrast, no such plateau behaviors were observed on either finite energy Caroli-de Genne-Matricon bound states or in the continuum of electronic states outside the superconducting gap. This unique behavior of the zero-mode conductance reaching a plateau strongly supports the existence of MZMs in this iron-based superconductor, which serves as a promising single-material platform for Majorana braiding at a relatively high temperature.

---
Source: https://tomesphere.com/paper/1904.06124