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MM: Fachverband Metall- und Materialphysik
MM 9: Poster
MM 9.46: Poster
Montag, 17. März 2025, 18:30–20:30, P1
Tuning intrinsic anomalous Hall effect from large to zero in two ferromagnetic states of SmMn2Ge2 — Mahima Singh1, Jyotirmoy Sau1, •Banik Rai1,2, Arunanshu Panda1, Manoranjan Kumar1, and Nitesh Kumar1 — 1S N Bose National Centre for Basic Sciences, Salt Lake City, Kolkata 700106, India — 2Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstraße 20, 01069 Dresden
The intrinsic anomalous Hall conductivity (AHC) in a ferromagnetic metal is determined by its band structure, with spin orientation being a key band structure tuning parameter. We study a layered tetragonal room temperature metallic ferromagnet SmMn2Ge2, which gives us the opportunity to study magneto-transport properties where both the c-axis and a-axis can be magnetically easy axes depending on the temperature range we choose. We show a moderately large fully intrinsic AHC up to room temperature when the crystal is magnetized along the c-axis. Interestingly, the AHC can be tuned to completely extrinsic with extremely large values when the crystal is magnetized along the a-axis, regardless of whether the a-axis is magnetically easy or hard. First principles calculations show that nodal line states originate from Mn-d orbitals just below the Fermi energy (EF) in the electronic band structure when the spins are oriented along the c-axis. Intrinsic AHC originates from the Berry curvature effect of the gapped nodal lines in the presence of spin-orbit coupling. AHC almost disappears when the spins are aligned along the a-axis as the nodal line states shift above EF and become unoccupied.
Keywords: Magneto-transport; Nodal line semimetal; Anomalous Hall effect; Berry curvature; Ferromagnet