Converting a topologically trivial superconductor into a topological superconductor via magnetic doping

TL;DR

This paper demonstrates how magnetic doping can induce a topological phase transition in a trivial superconductor, providing new pathways for experimental realization of topological superconductors.

Contribution

It reveals that magnetic disorder can turn a trivial superconductor into a topological one, contrasting with Anderson disorder effects, using both analytical and numerical methods.

Findings

Magnetic doping induces topological phase transitions in superconductors.

Anderson disorder drives topological superconductors into trivial phases.

Numerical solutions confirm the analytical predictions.

Abstract

We present a comparative theoretical study of the effects of standard Anderson and magnetic disorders on the topological phases of two-dimensional Rashba spin-orbit coupled superconductors, with the initial state to be either topologically trivial or nontrivial. Using the self-consistent Born approximation approach, we show that the presence of Anderson disorders will drive a topological superconductor into a topologically trivial superconductor in the weak coupling limit. Even more strikingly, a topologically trivial superconductor can be driven into a topological superconductor upon diluted doping of independent magnetic disorders, which gradually narrow, close, and reopen the quasi-particle gap in a nontrivial manner. These topological phase transitions are distinctly characterized by the changes in the corresponding topological invariants. The central findings made here are also confirmed using a complementary numerical approach by solving the Bogoliubov-de Gennes equations self-consistently within a tight-binding model. The present study offers appealing new schemes for potential experimental realization of topological superconductors.