Real-time dynamics of VCMA-assisted switching of magnetic tunnel junctions

TL;DR

This study explores the real-time dynamics of VCMA-assisted switching in magnetic tunnel junctions, revealing how device-specific effects influence switching speed and how increased voltage or magnetic field can reduce switching times to nanoseconds.

Contribution

It provides the first detailed real-time analysis of VCMA-assisted switching dynamics considering device-dependent effects and offers insights for optimizing magnetic memory and logic devices.

Findings

Charging effects and magnetic granularity limit switching speed near threshold

Higher voltage or magnetic field reduces switching delay to below a few nanoseconds

Micromagnetic simulations match experimental results, guiding device optimization

Abstract

Voltage control of magnetic anisotropy (VCMA) induced by charge accumulation is typically considered as an ultrafast process, enabling energy-efficient and high-speed magnetization switching in spintronic devices. In this work, we investigate the real-time dynamics of VCMA-assisted switching of magnetic tunnel junctions via relaxation in a magnetic field. We show that device-dependent charging effects and magnetic granularity in the free layer limit the switching speed at applied voltages close to the critical switching threshold. Increasing the voltage or the applied magnetic field reduces the incubation delay and total switching time to below a few ns. Micromagnetic simulations incorporating the finite charging times of the tunnel junction and the granularity of the magnetic film reproduce the experimental results, providing critical insights into optimizing VCMA-driven magnetization control for memory and logic applications.