Chiral Anomaly and Classical Negative Magnetoresistance of Weyl Metals
  We consider the classical magnetoresistance of a Weyl metal in which the electron Fermi surface possess nonzero fluxes of the Berry curvature. Such a system may exhibit large negative magnetoresistance with unusual anisotropy as a function of the angle between the electric and magnetic fields. In this case the system can support a new type of plasma waves. These phenomena are consequences of chiral anomaly in electron transport theory. 
D. T. Son and B. Z. Spivak
cond-mat.mes-hall