Gate-tunable large magnetoresistance in an all-semiconductor spin-transistor-like device

TL;DR

This paper demonstrates a large, gate-tunable magnetoresistance in a two-dimensional electron system, advancing spintronic device capabilities without relying on spin-orbit coupling.

Contribution

It introduces a novel all-semiconductor spin transistor-like device with electric field-tunable large magnetoresistance up to 80%.

Findings

Achieved up to 80% resistance change in a lateral 2DES-based spin valve.

Demonstrated electric gate control of magnetoresistance.

Showed spin-to-charge conversion enhancement via electric field effects.

Abstract

A large spin-dependent and electric field-tunable magnetoresistance of a two-dimensional electron system (2DES) is a key ingredient for the realization of many novel concepts for spin-based electronic devices. The low magnetoresistance observed during the last decades in devices with lateral semiconducting (SC) transport channels between ferromagnetic (FM) source (S) and drain (D) contacts has been the main obstacle for realizing spin field effect transistor proposals. Here, we show both, a large two terminal magnetoresistance in lateral 2DES-based spin valve geometry, with up to 80% resistance change, and tunability of the magnetoresistance by an electric gate. The large magnetoresistance is due to finite electric field effects at the FM/SC interface, which boost spin-to-charge conversion. The gating scheme we use is based on switching between uni- and bi-directional spin diffusion, without resorting to the spin-orbit coupling.