How to Enhance Anomalous Hall Effects in Magnetic Weyl Semimetal Co₃Sn₂S₂?

Abstract

Large spin−orbit coupling, kagome lattice, nontrivial topological band structure with inverted bands anticrossings, and Weyl nodes are essential ingredients ideally required to obtain maximal anomalous Hall effect (AHE) and are all present in Co 3 Sn 2 S 2 . It is a leading platform to show large intrinsic anomalous Hall conductivity (AHC) and giant anomalous Hall angle (AHA) simultaneously at low fields. The giant AHE in Co 3 Sn 2 S 2 is robust against small-scale doping-related chemical potential changes. In this work, we unveil a selective and cochemical doping route to maximize AHEs in Co 3 Sn 2 S 2 . To begin with, in Co 3 Sn 2−x In x S 2 , we brought the chemical potential at the hot spot of Berry curvature along with a maximum of asymmetric impurity scattering in the high mobility region. As a result, at x = 0.05, we found a significant enhancement of the AHA (95%) and AHC (190%) from the synergistic enhancement of extrinsic and intrinsic mechanisms due to the modified Berry curvature of gapped nodal lines. Later, with anticipation of further improvements in the AHE, we grew hole-codoped Co 3−y Fe y Sn 2−x In x S 2 crystals, where we surprisingly found a suppression of AHEs. The role of dopants in giving extrinsic effects or band broadening can be better understood if the chemical potential does not change on doping. By simultaneous and equal codoping with electrons and holes in Co 3−y−z Fe y Ni z Sn 2 S 2 , we kept the chemical potential unchanged. Henceforth, we found a significant enhancement in intrinsic AHC of ∼ 116% due to the disorder broadening in the kagome bands.