# Intrinsic Picosecond Magnetic Switching Mechanism Assisted by an Electric Field in a Synthetic Antiferromagnetic Structure

## TL;DR

This paper introduces a new picosecond magnetic switching mechanism in synthetic antiferromagnetic structures, utilizing electric field-controlled RKKY interaction to significantly reduce switching current and energy in STT-MRAM.

## Contribution

It presents a novel electric field-assisted switching mechanism in SAF structures, enabling ultrafast and low-energy magnetic switching for memory applications.

## Key findings

- Switching current density reduced by an order of magnitude at 100 ps
- Electric field controls sign change of RKKY interaction
- Enhanced energy contribution aids spin switching

## Abstract

The processional switching mechanism governs magnetic switching in magnetic tunnel junctions (MTJs) in the sub-nanosecond range, which limits the application of spin transfer torque magnetic random access memory (STT-MRAM) in the ultrafast region. In this paper, we propose a new picosecond magnetic switching mechanism in a synthetic antiferromagnetic (SAF) structure using the adjustable Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction controlled by an external electric field (E-field). It is shown that along with the sign change of the RKKY interaction in the SAF structure with an external E-field, the critical switching current density can be significantly reduced by one order of magnitude compared to that of a normal MTJ design at 100 ps; thus, this novel STT-MRAM can be written with a very low switching current density to avoid the MTJ breakdown problem and reduce the writing energy. To understand the physical origin of this abnormal phenomenon, a toy model is proposed in which the external-E-field-controlled sign change of the RKKY interaction in the SAF structure provides an extra contribution to the total energy that helps thespins overcome the energy barrier and break the processional switching mechanism.