Giant antisymmetric magnetoresistance arising across optically controlled domain walls in the magnetic Weyl semimetal Co3Sn2S2

Domain walls (DWs) in magnetic materials host various interesting magneto-transport phenomena. Recent theoretical proposals focusing on DWs of magnetic Weyl semimetals (mWSMs) suggest the emergence of even more exotic transport owing to topologically protected Weyl domains with opposite chirality. However, techniques for controlling and characterizing DWs in mWSMs have not yet matured sufficiently to identify the distinct features of electrical conduction on DWs. Here, by adopting an optical technique to manipulate magnetic domains in mWSM Co3Sn2S2 Hall-bar devices, we discover giant antisymmetric magnetoresistance arising across a DW formed by serially connected upward- and downward-magnetized Weyl domains. This phenomenon originates from the large tangent of the Hall angle associated with the intrinsic anomalous Hall effect in the oppositely magnetized Weyl domains. Furthermore, we quantitatively evaluate DW resistance by systematically controlling the number of DWs. These results underscore the promising avenue of Weyl DW engineering for advanced research on topological magnets. Domain walls in magnetic Weyl semimetals are a source of exotic transport owing to topologically protected domains with opposite chirality. Here, utilizing an optical technique to manipulate magnetic domains in Co3Sn2S2 Hall-bar devices, the authors discover giant antisymmetric magnetoresistance across a domain wall formed by serially connected upward- and downward-magnetized Weyl domains.