Topological Weyl semimetals provide ideal 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. See more in arXiv:1812.04339 (2018).

連絡教員　物理学系　村上修一（内線2747）