Beschreibung:
<jats:p>The combination of topology and magnetism has demonstrated great potential in the search of emergent quantum matters. In this study, we report the synthesis, magnetic, and electrical properties of GdAuPb, a rare-earth-based half-Heusler topological antiferromagnet candidate. Magnetization and specific heat studies reveal highly frustrated antiferromagnetic ordering of Gd at TN = 11.5 K. Interestingly, this material possesses a large, unsaturated magnetoresistance up to 800% below TN and anomalous Hall conductivity as large as 750 Ω−1cm−1 in the antiferromagnetic state. Moreover, the electric transports including the SdH quantum oscillation patterns all exhibit a sudden change around 9 T, indicating a field-driven quantum transition related to the Fermi surface reconstruction. These results suggest that GdAuPb is close to a topological critical point, which can be easily tuned via external parameters. Our study demonstrates a strong interplay between band topology and magnetism in GdAuPb and offers clues for material designs for topological antiferromagnets.</jats:p>