  Magnetic Weyl semimetals with broken time-reversal symmetry are expected to
generate strong intrinsic anomalous Hall effects, due to their large Berry
curvature. Here, we report a magnetic Weyl semimetal candidate Co3Sn2S2 with a
quasi-two-dimensional crystal structure consisting of stacked Kagome lattices.
This lattice provides an excellent platform for hosting exotic quantum
topological states. We observe a negative magnetoresistance that is consistent
with the chiral anomaly expected from the presence of Weyl fermions close to
the Fermi level. The anomalous Hall conductivity is robust against both
increased temperature and charge conductivity, which corroborates the intrinsic
Berry-curvature mechanism in momentum space. Owing to the low carrier density
in this material and the significantly enhanced Berry curvature from its band
structure, the anomalous Hall conductivity and the anomalous Hall angle
simultaneously reach 1130 S cm-1 and 20%, respectively, an order of magnitude
larger than typical magnetic systems. Combining the Kagome-lattice structure
and the long-range out-of-plane ferromagnetic order of Co3Sn2S2, we expect that
this material is an excellent candidate for observation of the quantum
anomalous Hall state in the two-dimensional limit.
