Topological van Hove singularities at phase transitions in Weyl metals

Abstract

We show that in three-dimensional (3D) topological metals, a subset of the van Hove singularities of the density of states sits exactly at the transitions between topological and trivial gapless phases. We may refer to these as topological van Hove singularities. By investigating two minimal models, we show that they originate from energy saddle points located between Weyl points with opposite chiralities, and we illustrate their topological nature through their magnetotransport properties in the ballistic regime. We exemplify the relation between van Hove singularities and topological phase transitions in Weyl systems by analyzing the 3D Hofstadter model, which offers a simple and interesting playground to consider different kinds of Weyl metals and to understand the features of their density of states. In this model, as a function of the magnetic flux, the occurrence of topological van Hove singularities can be explicitly checked.

7 pages + 5 pages appendix/references, 8 figures. v3: published version

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Cited by in corpus (6)

• Topological features in the ferromagnetic Weyl semimetal CeAlSi: Role of domain walls
• Tuning the nontrivial topological properties of the Weyl semimetal CeAlSi
• Pairwise annihilation of Weyl nodes induced by magnetic fields in the Hofstadter regime
• Designing Topological High-Order Van Hove Singularities: Twisted Bilayer Kagomé
• Magneto tunnel conductance across twisted Weyl semimetal junctions
• Critical magnetic flux for Weyl points in the three-dimensional Hofstadter model