Creating Weyl nodes and controlling their energy by magnetization rotation

Madhav Prasad Ghimire, Jorge I. Facio, Jhih Shih You, Linda Ye, Joseph G. Checkelsky, Shiang Fang, Efthimios Kaxiras, Manuel Richter, Jeroen Van Den Brink

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)

Abstract

As they do not rely on the presence of any crystal symmetry, Weyl nodes are robust topological features of an electronic structure that can occur at any momentum and energy. Acting as sinks and sources of Berry curvature, Weyl nodes have been predicted to strongly affect the transverse electronic response, like in the anomalous Hall or Nernst effects. However, to observe large anomalous effects the Weyl nodes need to be close to or at the Fermi level, which implies the band structure must be tuned by an external parameter, e.g., chemical doping. Here we show that in a ferromagnetic metal tuning of the Weyl node energy and momentum can be achieved by rotation of the magnetization. First, taking as example the elementary magnet hcp-Co, we use electronic structure calculations based on density-functional theory to show that by canting the magnetization away from the easy axis, Weyl nodes can be driven exactly to the Fermi surface. Second, we show that the same phenomenology applies to the kagome ferromagnet Co3Sn2S2, in which we additionally show how the dynamics in energy and momentum of the Weyl nodes affects the calculated anomalous Hall and Nernst conductivities. Our results highlight how the intrinsic magnetic anisotropy can be used to engineer Weyl physics.

Original languageEnglish
Article number032044
JournalPhysical Review Research
Volume1
Issue number3
DOIs
Publication statusPublished - 2019 Dec
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy

Fingerprint

Dive into the research topics of 'Creating Weyl nodes and controlling their energy by magnetization rotation'. Together they form a unique fingerprint.

Cite this