Anomalous Hall effect from strained-induced magnetic multipoles in antiferromagnetic material

The origin of anomalous Hall effect (AHE) in magnetic materials has been a central theme of condensed matter physics for a century. In ferromagnetic materials, the origin of AHE is from the magnetization. [1] On the other hand, the large AHE in antiferromagnetic Mn₃Sn without large magnetization was observed and its origin reamins elusive.[2] Recent theoretical study suggested that the hidden magnetic multipoles formed by the spin clusters can induce the large AHE in antiferromagnet. [3] Here, we establish the comprehensive connection between the large AHE in antiferromagnetic in-situ pyrochlore iridate Nd₂Ir₂O₇ thin film and strain-induced magnetic multipoles, T₁-octupole.

[1] Nagaosa, N. et al. Anomalous Hall effect. Rev. Mod. Phys. 82, 1539–1592 (2010).
[2] Suzuki, T. et al. Large anomalous Hall effect in a non-colinear antiferromagnet at room temperature. Nature 527, 212-215 (2015).
[3] Suzuki, M.-T., Koretsune, T., Ochi, M. & Arita, R. Cluster multipole theory for anomalous Hall effect in antiferromagnets. Phys. Rev. B 95, 94406 (2017).