Large intrinsic anomalous Hall effect in SrIrO3 induced by magnetic proximity effect

Abstract

The anomalous Hall effect (AHE) is an intriguing transport phenomenon occurring typically in ferromagnets as a consequence of broken time reversal symmetry and spin-orbit interaction. It can be caused by two microscopically distinct mechanisms, namely, by skew or side-jump scattering due to chiral features of the disorder scattering, or by an intrinsic contribution directly linked to the topological properties of the Bloch states. Here we show that the AHE can be artificially engineered in materials in which it is originally absent by combining the effects of symmetry breaking, spin orbit interaction and proximity-induced magnetism. In particular, we find a strikingly large AHE that emerges at the interface between a ferromagnetic manganite (La0.7Sr0.3MnO3) and a semimetallic iridate (SrIrO3). It is intrinsic and originates in the proximity-induced magnetism present in the narrow bands of strong spin-orbit coupling material SrIrO3, which yields values of anomalous Hall conductivity and Hall angle as high as those observed in bulk transition-metal ferromagnets. These results demonstrate the interplay between correlated electron physics and topological phenomena at interfaces between 3d ferromagnets and strong spin-orbit coupling 5d oxides and trace an exciting path towards future topological spintronics at oxide interfaces.

Direct Observation of Strong Anomalous Hall Effect and Proximity‐Induced Ferromagnetic State in SrIrO3

“…The sign of ρ xy AHE is always positive and opposite to that which has been recently discussed for SIO/manganite heterostructures. [ 34 ] Because of the insulating nature of LCO, the AHE unambiguously originates from the conductive SIO layer. This in turn indicates that underlying mechanism strongly relies on the related magnetic ion, Ir, which inherently shows a large SOC.…”

“…Nevertheless, theoretical analysis indicates strong enhancement of BC due to magnetic monopoles induced at avoided band crossings in the presence of strong SOC and magnetic order. [34] Adv. Mater.…”

“…In manganite/SIO superlattices magnetic exchange between the different layers may also result in interfacial FM properties. [26][27][28][29][30][31][32][33][34] These can in principle be probed through magnetotransport as effects such as the anomalous Hall effect (AHE) or the anisotropic magnetoresistance (AMR), two hallmarks of an FM metal, directly relate to, e.g., the magnetization, ordering temperature and anisotropy of the magnetic state and are therefore useful quantities to characterize the magnetic properties of materials.…”

Emergence of Insulating Ferrimagnetism and Perpendicular Magnetic Anisotropy in 3d–5d Perovskite Oxide Composite Films for Insulator Spintronics

“…2(d), indicating that the observed AHE is closely related to the PMA of LSMIO composite films. We note that interfacial magnetism and AHE has been intensively studied in LSMO/SIO superlattices and heterostructures 21,[40][41][42][43][44][45][46] . Our observed AHE is quite different from that the AHE reported in ref.…”

“…Our observed AHE is quite different from that the AHE reported in ref. 41, where a large AHE is originated from SIO layers due to magnetic proximity effect. Our AHE stems from the reflection of the spin current at the interface where an out-of-plane component (mz) of the LSMIO magnetization rotates the spin orientation of the spin current and generates a transverse voltage via the inverse spin Hall effect (ISHE).…”