Patterns and Thresholds of Magnetoelectric Switching in Spin Logic Devices

TL;DR

This paper investigates how magnetoelectric fields influence switching behavior in spintronic devices, revealing angle-dependent thresholds and dynamics through micromagnetic simulations for in-plane and out-of-plane magnetizations.

Contribution

It provides a detailed analysis of magnetoelectric switching thresholds and dynamics in spin logic devices, highlighting the role of domain wall formation and propagation.

Findings

Switching occurs via domain wall formation and propagation.

In-plane magnetization switches over a wide range of angles and fields.

Out-of-plane magnetization often fails due to domain wall reflection.

Abstract

In the quest to develop spintronic logic, it was discovered that magnetoelectric switching results in lower energy and shorter switching time than other mechanisms. Magnetoelectric (ME) field due to exchange bias at the interface with a multi-ferroic (such as BiFeO3) is well suited for 180 degree switching of magnetization. The ME field is determined by the direction of canted magnetization in BiFeO3 which can point at an angle to the plane, to which voltage is applied. Dependence of switching time and the threshold of ME field on its angles was determined by micromagnetic simulations. Switching occurs by formation of a domain wall on the side of the nanomagnet on top of BFO and its propagation to the rest of the magnet. For in-plane magnetization, switching occurs over a wide range of angles and at all magnitudes of ME field above threshold. For out-of-plane magnetization failure occurs (with an exception of a narrow range of angles and magnitudes of ME field) due to the domain wall reflecting from the opposite end of the nanomagnet.