Topological charge and heat transport in Weyl semimetals
Topological Weyl semimetals provide fascinating platforms to examine exotic transport phenomena such as the chiral anomaly and the anomalous Hall effect. In the ordinary (longitudinal) transport, the Wiedemann-Franz law links the ratio of electronic charge and heat conductivity to a fundamental constant. It has been tested in numerous solids, but the extent of its relevance to the anomalous (transverse) transport remains an open question. I will introduce recently-discovered magnetic Weyl materials Mn3Sn and Mn3Ge. Their noncollinear chiral spin structure induces huge anomalous Hall effect and thermal Hall effect in a Kagome-type lattice. In collaboration with experiment, we reveal a finite temperature violation of the Wiedemann-Franz correlation. This violation is caused by the Berry curvature distribution, rather than the inelastic scattering as observed in ordinary metals.