Field modulated anomalous Hall conductivity and planar Hall effect in Co3Sn2S2 nanoflakes

Time-reversal-symmetry-breaking Weyl semimetals (WSMs) have attracted great attention recently because of the interplay between intrinsic magnetism and topologically nontrivial electrons [1-6]. Here, we present anomalous Hall effect (AHE) and planar Hall effect (PHE) studies on nanoflakes of Co3Sn2S2, a magnetic WSM hosting a stacked Kagome lattice. The reduced thickness modifies the magnetic properties of the nanoflake, resulting in a 15-time larger coercive field compared with the bulk [3], and correspondingly also modifies the transport properties. A 22% enhancement of the intrinsic anomalous Hall conductivity (AHC), as compared to bulk material, was observed. A magnetic field modulated AHC, which may be directly related to the changing Weyl point separation with magnetic field, was also found. Furthermore, we showed that the PHE in a hard magnetic WSM is a complex interplay between ferromagnetism, orbital magnetoresistance and the chiral anomaly. Our findings pave the way for a further understanding of exotic transport features in the burgeoning field of magnetic topological phases.