Single Magnetic Atom on a Surface: Anisotropy Energy and Spin Density

TL;DR

This paper computationally investigates the magnetic anisotropy of a single Dysprosium atom on a copper-nitrite surface, revealing record-high anisotropy energy and novel analysis methods for rare-earth atoms.

Contribution

It presents the first computational study of a single rare-earth atom's magnetic anisotropy on a surface and introduces new symmetry-based analysis techniques.

Findings

Record-high magnetic anisotropy energy of 31 meV for Dy on the surface.

Unconventional f and d subshell symmetries enable simplified spin-density analysis.

First-principles calculations demonstrate enhanced magnetic properties of single rare-earth atoms.

Abstract

Studying single-atom magnetic anisotropy on surfaces enables the exploration of the smallest magnetic storage bit that can be built. In this work, magnetic anisotropy of a single rare-earth atom on a surface is studied computationally for the first time. The single adatom and its substrate surface are chosen to be a Dysprosium (Dy) atom and a copper-nitrite surface, respectively, where single transition-metal magnetic atoms on the same surface were previously studied one atom at a time by scanning tunneling microscopes. We propose unconventional f and d subshell symmetries so that following the first-principles calculations, simple pictorial analyses of the spin-density distribution can be performed for the first time, independently for both a rare-earth atom Dy and a transition-metal Fe. The magnetic anisotropy energy of Dy on the surface is calculated to be a factor of five larger than the previous highest one, reaching a record-high value of 31 meV.