The chiral anomaly and thermopower of Weyl fermions in the half-Heusler   GdPtBi
  The Dirac and Weyl semimetals are unusual materials in which the nodes of the bulk states are protected against gap formation by crystalline symmetry. The chiral anomaly~\cite{Adler,Bell}, predicted to occur in both systems, was recently observed as a negative longitudinal magnetoresistance (LMR) in Na$_3$Bi and in TaAs. An important issue is whether Weyl physics appears in a broader class of materials. We report evidence for the chiral anomaly in the half-Heusler GdPtBi. In zero field, GdPtBi is a zero-gap semiconductor with quadratic bands. In a magnetic field, the Zeeman energy leads to Weyl nodes. We have observed a large negative LMR with the field-steering properties specific to the chiral anomaly. The chiral anomaly also induces strong suppression of the thermopower. We report a detailed study of the thermoelectric response function $\alpha_{xx}$ of Weyl fermions. The scheme of creating Weyl nodes from quadratic bands suggests that the chiral anomaly may be observable in a broad class of semimetals. 
Max Hirschberger, Satya Kushwaha, Zhijun Wang, Quinn Gibson, Carina A.   Belvin, B. A. Bernevig, R. J. Cava and N. P. Ong
cond-mat.str-el