Tailoring Elastic Scattering of Relativistic Antiferromagnetic Domain Walls for Collision-based Computing

TL;DR

This paper investigates the conditions under which antiferromagnetic domain walls exhibit elastic or inelastic collisions, providing insights crucial for developing soliton-based computing in antiferromagnetic spintronics.

Contribution

It demonstrates the conditions for elastic and inelastic scattering of antiferromagnetic domain walls and presents a phase diagram based on spin-orbit field parameters.

Findings

Elastic scattering occurs at minimum domain wall speeds.

Inelastic collisions produce dispersing breathers.

A phase diagram maps scattering behavior to field strength and duration.

Abstract

Soliton-based computing is relied on their unique properties for transporting energy and emerging intact from head-on collisions. Magnetic domain walls are often referred to as solitons disregarding the strict mathematical definition requiring the above scattering property. Here we demonstrate the conditions of elastic and inelastic scattering for spin-orbit torque-induced dynamics of antiferromagnetic domain walls on the example of a technologically relevant Mn$_2$Au material. We show that even domain walls with opposite winding numbers can experience elastic scattering and we present a corresponding phase diagram as a function of the spin-orbit field strength and duration. The elastic collision requires minimum domain walls speed which we explain assuming an attractive potential created by domain wall pair. On the contrary, when the domain walls move at lower speeds, their collision is inelastic and results in a dispersing breather. Our findings will be important for the development soliton-based computing using antiferromagnetic spintronics and we discuss these perspective on our suggestions of how to create NOT and XOR gates.