Domain Walls in a Row-Wise Antiferromagnetic Mn Monolayer

TL;DR

This paper studies magnetic domain walls in a single Mn monolayer on Re(0001), revealing a new type of domain wall with unique properties influenced by the low symmetry of the antiferromagnetic state.

Contribution

It introduces a novel domain wall type connecting 1Q domains via a transient 2Q state, characterized by a 90° angle, and explores their properties through experimental and simulation methods.

Findings

Discovery of a new domain wall type with 90° angles

Domain wall width of about 2 nm from exchange interactions

Anisotropic force required to move atoms at the domain wall

Abstract

We investigate magnetic domain walls in a single fcc Mn layer on Re(0001) employing spin-polarized STM, atom manipulation, and spin dynamics simulations. The low symmetry of the row-wise antiferromagnetic (1Q) state leads to a new type of domain wall which connects rotational 1Q domains by a transient 2Q state with characteristic 90$^\circ$ angles between neighboring magnetic moments. The domain wall properties depend on their orientation and their width of about 2 nm essentially results from a balance of Heisenberg and higher-order exchange interactions. Atom manipulation allows domain wall imaging with atomic spin-resolution, as well as domain wall positioning, and we demonstrate that the force to move an atom is anisotropic on the 1Q domain.