Local control of single atom magneto-crystalline anisotropy

TL;DR

This study demonstrates that local strain from a nearby atom can controllably modify the magnetic anisotropy of a single Fe atom on a surface, revealing a new method for atomic-scale magnetic control.

Contribution

It introduces a method to locally control single atom magnetic anisotropy using atom manipulation and strain effects, supported by a qualitative first-principles model.

Findings

Local strain from a second Fe atom alters magnetic anisotropy.

Anisotropy can be enhanced or reduced depending on atom positions.

A qualitative first-principles model explains the observed behavior.

Abstract

Individual Fe atoms on a Cu2N/Cu(100) surface exhibit strong magnetic anisotropy due to the crystal field. Using atom manipulation in a low-temperature STM we demonstrate that the anisotropy of one Fe atom is significantly influenced by local strain due to a second Fe atom placed nearby. Depending on the relative positions of the two atoms on the Cu2N lattice we can controllably enhance or reduce the uniaxial anisotropy. We present a model that explains the observed behavior qualitatively in terms of first principles.