  We provide a review of recent experimental results on the chiral anomaly in
Dirac/Weyl semimetals. After a brief introduction, we trace the steps leading
to the prediction of materials that feature protected 3D bulk Dirac nodes. The
chiral anomaly is presented in terms of charge pumping between the chiral
Landau levels of Weyl fermions in parallel electric and magnetic fields. The
related chiral magnetic effect and chiral zero sound are described. Current
jetting effects, which present major complications in experiments on the
longitudinal magnetoresistance, are carefully analyzed. We describe a recent
test that is capable of distinguishing these semiclassical artifacts from
intrinsic quantum effects. Turning to experiments, we review critically the
longitudinal magnetoresistance experiments in the Dirac/Weyl semimetals Na3Bi,
GdPtBi, ZrTe5 and TaAs. Alternate approaches to the chiral anomaly, including
experiments on non-local transport, thermopower, thermal conductivity and
optical pump-probe response are reviewed. In the Supplement, we provide a brief
discussion of the chiral anomaly in the broader context of high energy physics
and relativistic quantum field theory, as well the anomaly's starring role at
the nexus of quantum physics and differential geometry.

Strongly Correlated Electrons;High Energy Physics - Theory