Direct observation of strong anomalous Hall effect and proximity-induced ferromagnetic state in SrIrO3

TL;DR

This study demonstrates a proximity-induced ferromagnetic state in SrIrO3 heterostructures, revealing a strong anomalous Hall effect and pseudospin-lattice coupling, highlighting the tunability of topological properties in 5d iridates.

Contribution

It provides direct observation of ferromagnetism and anomalous Hall effect in SrIrO3 via interface engineering with a ferromagnetic insulator, revealing new magnetic and topological phenomena.

Findings

Proximity-induced ferromagnetism with TC = 100 K in SrIrO3.

Observation of a large anomalous Hall effect with Hall angle much greater than in 3d metals.

Detection of a strong pseudospin-lattice coupling below 20 K.

Abstract

The 5d iridium-based transition metal oxides have gained broad interest because of their strong spin-orbit coupling which favors new or exotic quantum electronic states. On the other hand, they rarely exhibit more mainstream orders like ferromagnetism due to generally weak electron-electron correlation strength. Here, we show a proximity-induced ferromagnetic (FM) state with TC = 100 K and strong magnetocrystalline anisotropy in a SrIrO3 (SIO) heterostructure via interfacial charge transfer by using a ferromagnetic insulator in contact with SIO. Electrical transport allows to selectively probe the FM state of the SIO layer and the direct observation of a strong, intrinsic and positive anomalous Hall effect (AHE). For T < 20 K, the AHE displays unusually large coercive and saturation field, a fingerprint of a strong pseudospin-lattice coupling. A Hall angle, sxyAHE/sxx, larger by an order of magnitude than in typical 3d metals and a FM net moment of about 0.1 mB/Ir, is reported. This emphasizes how efficiently the nontrivial topological band properties of SIO can be manipulated by structural modifications and the exchange interaction with 3d TMOs.