Gate-voltage switching of non-reciprocal transport in oxide-based Rashba interfaces

TL;DR

This paper demonstrates that gate voltage can control the sign of the Edelstein effect in SrTiO3 2DEGs, enabling potential applications in gate-tunable non-reciprocal electronic devices.

Contribution

It introduces gate voltage as a control parameter for the Edelstein effect in oxide-based Rashba interfaces, a novel approach for spintronic device manipulation.

Findings

Gate voltage reverses the sign of the Edelstein effect.

Proposed logic devices utilize dual control of spin density.

Potential for gate-tunable non-reciprocal electronics.

Abstract

The linear magnetoelectric effect (ME) is the phenomenon by which an electric field produces a magnetization. Its observation requires both time-reversal and space-inversion symmetries to be broken, as in multiferroics. While the ME effect has only been studied in insulating materials, it can actually exist in non-centrosymmetric conductors such as two-dimensional electron gases (2DEGs) with Rashba spin-orbit coupling. It is then coined the Edelstein effect (EE), by which a bias voltage -- generating a charge current -- produces a transverse spin density, i.e. a magnetization. Interestingly, 2D systems are sensitive to voltage gating, which provides an extra handle to control the EE. Here, we show that the sign of the EE in a SrTiO$_3$ 2DEG can be controlled by a gate voltage. We propose various logic devices harnessing the dual control of the spin density by current and gate voltages and discuss the potential of our findings for gate-tunable non-reciprocal electronics.