Large current modulation and tunneling magnetoresistance change by a side-gate electric field in a GaMnAs-based vertical spin metal-oxide-semiconductor field-effect transistor

TL;DR

This study demonstrates a GaMnAs-based vertical spin MOSFET with significant current modulation and tunable tunneling magnetoresistance, driven by electric field effects on tunneling and magnetic anisotropy, advancing high-performance spintronic devices.

Contribution

The paper reports the largest current modulation ratio in vertical spin MOSFETs and reveals electric field control of tunneling magnetoresistance and magnetic anisotropy in a GaMnAs-based device.

Findings

Drain-source current modulation ratio up to 130%

Tunneling magnetoresistance ratio up to ~7%

Electric field modulates magnetic anisotropy and TMR ratio

Abstract

A vertical spin metal-oxide-semiconductor field-effect transistor (spin MOSFET) is a promising low-power device for the post scaling era. Here, using a ferromagnetic-semiconductor GaMnAs-based vertical spin MOSFET with a GaAs channel layer, we demonstrate a large drain-source current IDS modulation by a gate-source voltage VGS with a modulation ratio up to 130%, which is the largest value that has ever been reported for vertical spin field-effect transistors thus far. We find that the electric field effect on indirect tunneling via defect states in the GaAs channel layer is responsible for the large IDS modulation. This device shows a tunneling magnetoresistance (TMR) ratio up to ~7%, which is larger than that of the planar-type spin MOSFETs, indicating that IDS can be controlled by the magnetization configuration. Furthermore, we find that the TMR ratio can be modulated by VGS. This result mainly originates from the electric field modulation of the magnetic anisotropy of the GaMnAs ferromagnetic electrodes as well as the potential modulation of the nonmagnetic semiconductor GaAs channel layer. Our findings provide important progress towards high-performance vertical spin MOSFETs.