How to realize a robust practical Majorana chain in a quantum dot-superconductor linear array

TL;DR

This paper proposes a quantum dot-superconductor array as a robust platform for realizing Majorana fermions, resilient to disorder, by mapping it to a topological Kitaev chain in a practical experimental setup.

Contribution

It introduces a disordered quantum dot-superconductor chain that can host Majorana modes, demonstrating robustness and tunability for topological quantum computing.

Findings

Majorana modes can exist in disordered quantum dot chains

The system maps to a 1D Kitaev chain in a suitable regime

Robust topological phase achieved despite strong disorder

Abstract

Semiconducting nanowires in proximity to superconductors are promising experimental systems for Majorana fermions, which may ultimately be used as building blocks for topological quantum computers. A serious challenge in the experimental realization of the Majorana fermions is the supression of topological superconductivity by disorder. We show that Majorana fermions protected by a robust topological gap can occur at the ends of a chain of quantum dots connected by s-wave superconductors. In the appropriate parameter regime, we establish that the quantum dot/superconductor system is equivalent to a 1D Kitaev chain, which can be tuned to be in a robust topological phase with Majorana end modes even in the case where the quantum dots and superconductors are both strongly disordered. Such a spin-orbit coupled quantum dot - s-wave superconductor array provides an ideal experimental platform for the observation of non-Abelian Majorana modes.