Multi-scale modelling of current-induced switching in magnetic tunnel junctions using ab initio spin transfer torques

TL;DR

This paper presents a multi-scale approach combining ab initio calculations and atomistic spin dynamics to analyze and optimize current-induced switching in magnetic tunnel junctions, aiding the design of efficient magnetic memory devices.

Contribution

It introduces a novel multi-scale methodology integrating ab initio spin transfer torque calculations with large-scale spin dynamics simulations for magnetic tunnel junctions.

Findings

Spin torques mainly act at the Co/MgO interface.

Calculated switching times and critical currents for the prototype junction.

Framework accounts for detailed material properties in device design.

Abstract

There exists a significant challenge in developing efficient magnetic tunnel junctions with low write currents for non-volatile memory devices. With the aim of analysing potential materials for efficient current-operated magnetic junctions we have developed a multi-scale methodology combining the ab initio calculations of spin-transfer torque with large-scale time-dependent simulations using atomistic spin dynamics. In this work we introduce our multi-scale approach including a discussion on a number of possible mapping schemes the ab initio spin torques into the spin dynamics. We demonstrate this methodology on a prototype Co/MgO/Co/Cu tunnel junction showing that the spin torques are primarily acting at the interface between the Co free layer and MgO. Using spin dynamics we then calculate the reversal switching times for the free layer and the critical voltages and currents required for such switching. Our work provides an efficient, accurate and versatile framework for designing novel current-operated magnetic devices, where all the materials details are take into account.