Boosting the intrinsic anomalous Hall effect through a topological phase transition in the magnetic Weyl semimetal Co3Sn2S2

Abstract

The anomalous Hall Effect (AHE) is one of the most fundamental phenomena related to band topology and holds great potential for technological applications. A promising approach to search for large AHE is to begin with a magnetic Weyl semimetal (WSM) and manipulate the Weyl nodes in the momentum-energy $(k\ensuremath{-}E)$ space. However, controlling the Weyl points is generally difficult because Weyl nodes can robustly exist at a generic momentum. Here we realize this approach in an experimentally confirmed ferromagnetic WSM ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ via tension. Our calculations systematically demonstrate that the tension applied to ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ can drive the movement and annihilation of Weyl nodes in the $k\ensuremath{-}E$ space, triggering a high-Chern-number three-dimensional quantum AHE topological phase transition and thus greatly boosting the AHE. We also found a rare way of annihilation of Weyl nodes occurring near the Brillouin zone boundary. Our work offers a promising way to boost the AHE and sheds light on the search for three-dimensional quantum anomalous Hall insulators.