Disorder effects on triple-point fermions

Hsiu Chuan Hsu, Ion Cosma Fulga, Jhih Shih You

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The stability of three-dimensional relativistic semimetals to disorder has recently attracted great attention, but the effect of disorder remains elusive for multifold fermions, that are not present in the framework of quantum field theory. In this paper, we investigate one type of multifold fermions, so-called triple-point fermions (TPFs), which have pseudospin-1 degrees of freedom and topological charges ±2. Specifically, we consider the effect of disorder on a minimal, three-band tight-binding model, which realizes the minimal number of two TPFs. The numerically obtained, disorder-averaged density of states suggests that, within a finite energy window, the TPFs are robust up to a critical strength of disorder. In the strong disorder regime, the inter-TPF scattering is the main mechanism for destroying a single TPF. Moreover, we study the effects of disorder on the distribution of Fermi arcs and surface Berry curvature. We demonstrate that the Fermi arc retains its sharpness at weak disorder, but gradually dissolves into the metallic bulk for stronger disorder. In the clean limit, the surface Berry curvature exhibits a bipolar configuration in the surface Brillouin zone. With increasing disorder, the positive and negative surface Berry curvatures start to merge at the nearby momenta where the Fermi arcs penetrate into bulk.

Original languageEnglish
Article number245118
JournalPhysical Review B
Volume106
Issue number24
DOIs
Publication statusPublished - 2022 Dec 15

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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