Time-reversal symmetric topological superconductivity in Machida-Shibata lattices

Fuente: arXiv
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Main Authors: Ioannidis, Ioannis, Chiu, Ching-Kai, Posske, Thore
Format: Preprint
Published: 2025
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author Ioannidis, Ioannis
Chiu, Ching-Kai
Posske, Thore
author_facet Ioannidis, Ioannis
Chiu, Ching-Kai
Posske, Thore
contents Recent experiments engineered special spin-degenerate Andreev bound states in atomic cages of adatoms on superconductors, the Machida-Shibata states, a promising building block for quantum matter. Here, we investigate the formation of time-reversal symmetric bands by hybridizing multiple such states and analyzing their electronic topological properties assuming small on-site electron repulsion. The low-energy theory shows that competing emerging singlet and triplet superconducting pairings drive the formation of topologically non-trivial phases in symmetry class DIII. We, therefore, predict Kramers pairs of Majorana zero modes appear at the ends of Machida-Shibata chains, while two-dimensional lattices host helical Majorana edge modes. Additionally, we discover extended regions in the Brillouin zone with vanishing superconducting pairings, which are lifted by the repulsive electron interactions. Our findings offer new perspectives for manipulating topological superconductivity and pairings in non-magnetic adatom systems.
format Preprint
id arxiv_https___arxiv_org_abs_2504_08674
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Time-reversal symmetric topological superconductivity in Machida-Shibata lattices
Ioannidis, Ioannis
Chiu, Ching-Kai
Posske, Thore
Superconductivity
Mesoscale and Nanoscale Physics
Recent experiments engineered special spin-degenerate Andreev bound states in atomic cages of adatoms on superconductors, the Machida-Shibata states, a promising building block for quantum matter. Here, we investigate the formation of time-reversal symmetric bands by hybridizing multiple such states and analyzing their electronic topological properties assuming small on-site electron repulsion. The low-energy theory shows that competing emerging singlet and triplet superconducting pairings drive the formation of topologically non-trivial phases in symmetry class DIII. We, therefore, predict Kramers pairs of Majorana zero modes appear at the ends of Machida-Shibata chains, while two-dimensional lattices host helical Majorana edge modes. Additionally, we discover extended regions in the Brillouin zone with vanishing superconducting pairings, which are lifted by the repulsive electron interactions. Our findings offer new perspectives for manipulating topological superconductivity and pairings in non-magnetic adatom systems.
title Time-reversal symmetric topological superconductivity in Machida-Shibata lattices
topic Superconductivity
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2504.08674