Tunneling anisotropic spin galvanic effect

TL;DR

This paper demonstrates that spin injection through a tunnel barrier into a system with broken inversion symmetry can generate a transverse charge current, exhibiting strong anisotropy due to complex spin-orbit interactions, relevant for oxide interfaces.

Contribution

It introduces a tunneling spin galvanic effect that is robust, non-local, and anisotropic, highlighting new mechanisms for spin-charge conversion in layered systems.

Findings

The effect produces a transverse charge current from pure spin injection.

The anisotropy depends on the angular dependence of the internal spin-orbit field.

The effect is robust to disorder and non-local configurations.

Abstract

We show that pure spin injection from a magnetic electrode into an inversion symmetry-broken system composed of a tunnel barrier and a metallic region generates a transverse charge current. Such a tunnelling spin galvanic conversion is robust to disorder and non-local, i.e. injection and detection contacts do not coincide, and is strongly anisotropic whenever the internal spin-orbit field has a non-trivial angular dependence. The anisotropy shows up in linear response, contrary to what happens in bulk conversion setups lacking tunnelling elements. This is particularly relevant for spin-charge conversion at oxide interfaces, where both the tunnel barrier and the receiving low-dimensional metallic system host effective spin-orbit fields with complex angular symmetries.