Giant Intrinsic Spin and Orbital Hall Effects in Sr2MO4 (M=Ru,Rh,Mo)

TL;DR

This paper demonstrates giant intrinsic spin and orbital Hall effects in Sr2MO4 compounds due to d-orbital angular momentum and spin-orbit coupling, suggesting potential for advanced spintronics and orbitronics applications.

Contribution

It reveals the origin of large Hall conductivities in Sr2MO4 and predicts their ubiquity in multiorbital transition metal systems, advancing understanding of intrinsic Hall effects.

Findings

Giant spin Hall conductivity in Sr2MO4

Large orbital Hall conductivity observed

Mechanism linked to effective Aharonov-Bohm phase

Abstract

We investigate the intrinsic spin Hall conductivity (SHC) and the d-orbital Hall conductivity (OHC) in metallic d-electron systems, by focusing on the t_{2g}-orbital tight-binding model for Sr2MO4 (M=Ru,Rh,Mo). The conductivities obtained are one or two orders of magnitude larger than predicted values for p-type semiconductors with 5% hole doping. The origin of these giant Hall effects is the ``effective Aharonov-Bohm phase'' that is induced by the d-atomic angular momentum in connection with the spin-orbit interaction and the inter-orbital hopping integrals. The huge SHC and OHC generated by this mechanism are expected to be ubiquitous in multiorbital transition metal complexes, which pens the possibility of realizing spintronics as well as orbitronics devices.