Quantum magnetism and topological superconductivity in Yu-Shiba-Rusinov chains

TL;DR

This paper investigates dilute Yu-Shiba-Rusinov chains as a flexible platform for quantum magnetism and topological superconductivity, deriving an extended model to analyze their phase diagram and tunneling spectra.

Contribution

It introduces an extended $t-J$ model for dilute quantum YSR chains, highlighting their potential for realizing topological superconducting phases with quantum magnetic properties.

Findings

Derived an extended $t-J$ model for YSR chains.

Analyzed the phase diagram and tunneling spectra.

Explored quantum magnetism's role in topological phases.

Abstract

Chains of magnetic adatoms on superconductors have been discussed as promising systems for realizing Majorana end states. Here, we show that dilute Yu-Shiba-Rusinov (YSR) chains are also a versatile platform for quantum magnetism and correlated electron dynamics, with widely adjustable spin values and couplings. Focusing on subgap excitations, we derive an extended $t-J$ model for dilute quantum YSR chains and use it to study the phase diagram as well as tunneling spectra. We explore the implications of quantum magnetism for the formation of a topological superconducting phase, contrasting it to existing models assuming classical spin textures.