# Non-volatile electric control of spin-orbit torques in an oxide two-dimensional electron gas

**Authors:** Cécile Grezes, Aurélie Kandazoglou, Maxen Cosset-Cheneau, Luis Arche, Paul Noël, Paolo Sgarro, Stephane Auffret, Kevin Garello, Manuel Bibes, Laurent Vila, Jean-Philippe Attané  
**arXiv:** [2206.03068](https://arxiv.org/abs/2206.03068)  
**Date:** 2022-06-07  
**Summary page:** https://www.summarizepaper.com/en/paper/2206.03068v1/

## Key points

- Spin-orbit torques (SOTs) can manipulate magnetization using in-plane current
- Two-dimensional electron gases (2DEGs) at oxide interfaces can efficiently convert spin-to-charge currents
- Gate voltages offer a degree of freedom not available in classical ferromagnetic/spin Hall effect bilayers for spin-orbitronics
- Researchers successfully demonstrated non-volatile electric-field control of SOTs in an oxide-based Rashba–Edelstein 2DEG
- This achievement opens up new possibilities for electrically reconfigurable SOT MRAM circuits, SOT oscillators, skyrmion and domain wall based devices, and magnonic circuits
- The study was conducted on a 2DEG–CoFeB/MgO heterostructure with large perpendicular magnetization
- By controlling the gate voltage applied to the oxide layer, researchers were able to switch between two stable states of the 2DEG with different conductivities
- This change in conductivity led to a corresponding change in the magnitude and direction of SOTs generated by an inplane current passing through the CoFeB layer
- The researchers found that they could control both the amplitude and sign of these SOTs nonvolatilely
- This breakthrough validates the compatibility of oxide 2DEGs for magnetic tunnel junction integration
- It paves the way for developing novel devices based on electrically controllable SOTs such as MRAMs, oscillators, and magnonic circuits.

## Summary

Spin-orbit torques (SOTs) have emerged as a promising way to manipulate magnetization using in-plane current, with the potential to revolutionize information technologies by enabling fast and low-power devices. Recently, it has been shown that two-dimensional electron gases (2DEGs) at oxide interfaces can efficiently convert spin-to-charge currents. The ability to control 2DEGs using gate voltages offers a degree of freedom not available in classical ferromagnetic/spin Hall effect bilayers for spin-orbitronics, where the sign and amplitude of SOTs are fixed by the stack structure. In this study, researchers report on their successful non-volatile electric-field control of SOTs in an oxide-based Rashba–Edelstein 2DEG. They demonstrate that the 2DEG can be controlled using a backgate electric field, providing two remanent and switchable states with a large resistance contrast of 1064%. This achievement opens up new possibilities for electrically reconfigurable SOT MRAM circuits, SOT oscillators, skyrmion and domain wall based devices, and magnonic circuits. The study was conducted on a 2DEG–CoFeB/MgO heterostructure with large perpendicular magnetization. By controlling the gate voltage applied to the oxide layer, researchers were able to switch between two stable states of the 2DEG with different conductivities. This change in conductivity led to a corresponding change in the magnitude and direction of SOTs generated by an inplane current passing through the CoFeB layer. The researchers found that they could control both the amplitude and sign of these SOTs nonvolatilely. This breakthrough is significant because it validates the compatibility of oxide 2DEGs for magnetic tunnel junction integration. It also paves the way for developing novel devices based on electrically controllable SOTs such as MRAMs, oscillators, and magnonic circuits. The ability to control SOTs electrically in a nonvolatile way using gate voltages offers a new degree of freedom for designing spin–orbitronic devices with improved functionality and energy efficiency.