Giant anomalous thermal Hall effect in tilted type-I magnetic Weyl semimetal Co3Sn2S2

The recent discovery of magnetic Weyl semimetal ${\mathrm{Co}}₃{\mathrm{Sn}}₂{\mathrm{S}}₂$ opens up new avenues for research into the interactions between topological orders, magnetism, and electronic correlations. Motivated by the observations of a large anomalous Hall effect because of large Berry curvature, we investigate another Berry curvature-induced phenomenon, namely the anomalous thermal Hall effect in ${\mathrm{Co}}₃{\mathrm{Sn}}₂{\mathrm{S}}₂$. We study it with and without strain, using a Wannier tight-binding Hamiltonian derived from first-principles density functional theory calculations. We first identify this material as a tilted type-I Weyl semimetal based on the band-structure calculation. Within the quasiclassical framework of Boltzmann transport theory, a giant anomalous thermal Hall signal appears due to the presence of large Berry curvature. Surprisingly, the thermal Hall current changes and even undergoes a sign-reversal upon varying the chemical potential. Furthermore, applying about 13 GPa stress, an enhancement as large as 33% in the conductivity is observed; however, the tilt vanishes along the path connecting the Weyl nodes. In addition, we have confirmed the validity of the Wiedemann-Franz law in this system for anomalous transports. We propose specific observable signatures that can be directly tested in experiments.