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arXiv · 2110.10686

Weyl Nodal-Ring Semimetallic Behavior and Topological Superconductivity in Crystalline Forms of Su-Schrieffer-Heeger Chains

Peter Rosenberg·Efstratios Manousakis
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Abstract

We consider a three-dimensional model of coupled Su-Schrieffer-Heeger (SSH) chains. The analytically soluble model discussed here reliably reproduces the features of the band structure of crystalline polyacetylene as obtained from density-functional theory. We show that when a certain inter-chain coupling is sufficiently increased, the system develops a ring of Weyl nodes. We argue that such an increase could be achieved experimentally by intercalation or extreme pressure. With the addition of a simple intra-orbital pairing term we find that the system supports an exotic superconducting state with drumhead surface states and annular Majorana states localized on the surface. In addition to suggesting a novel real material realization of a nodal ring semimetal and possibly topological superconductivity, our results provide a new perspective on the SSH model, demonstrating that a simple extension of this broadly-impacting model can once again provide fundamental insights on the topological behavior of condensed matter systems.

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Peter Rosenberg, Efstratios Manousakis. 2021-10-20. Weyl Nodal-Ring Semimetallic Behavior and Topological Superconductivity in Crystalline Forms of Su-Schrieffer-Heeger Chains. https://doi.org/10.1103/physrevb.104.134511

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