Giant Anomalous Hall Conductivity in a Topological Nodal‐Chain L1 2 ‐Fe 3 Ga: Intrinsic and Extrinsic Origins

Le résumé fourni par la source

Abstract Nodal chain materials exhibit exceptional intrinsic anomalous transport properties due to their unique topological band structures. Here, L1 2 phase Fe 3 Ga is identified as a nodal chain metal, achieving a giant anomalous Hall conductivity (AHC) of ≈1939 S cm −1 at 10 K and 1007 S cm −1 at 300 K in polycrystalline, highlighting remarkable temperature robustness due to the significant intrinsic contribution of 1129 S cm −1 . The AHC of 1939 S cm −1 arises from a combination of intrinsic and extrinsic mechanisms, surpassing that of several prominent Weyl/nodal‐line semi‐metals, like Co 3 Sn 2 S 2 (1130 S cm −1 at 2 K). The giant intrinsic AHC originates from Berry curvature induced by a nodal chain structure, composed of two interconnected nodal rings 22 meV above the Fermi level ( E F ). The large extrinsic AHC, ≈810 S cm −1 at 10 K stems from scattering associated with minor D0 3 phase impurities. Ga doping in Fe 3‐ x Ga 1+ x triggers a Lifshitz transition at E F , shifting carrier dominance from holes to electrons, and enhances the anomalous Hall angle to 8.6% at x = 0.08 while maintaining a large intrinsic AHC. This work establishes L1 2 phase Fe 3 Ga as an ideal platform for topological studies and magnetic sensor applications based on its giant AHC.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.