Adsorption, Segregation and Magnetization of a Single Mn Adatom on the GaAs (110) Surface

TL;DR

This study uses density functional calculations to explore how a single Mn atom adsorbs, moves, segregates, and magnetizes on the GaAs(110) surface, revealing insights into its mobility, electronic structure, and STM visibility.

Contribution

It provides detailed computational analysis of Mn adatom behavior on GaAs(110), including energy barriers and electronic states, which was not previously characterized.

Findings

Mn adatom is mobile along the trench with a 0.56 eV barrier.

Segregation across trenches has a high barrier of 1.67 eV.

Density of states shows a wide gap in majority spin and gap states in minority spin.

Abstract

Density functional calculations with a large unit cell have been conducted to investigate adsorption, segregation and magnetization of Mn monomer on GaAs(110). The Mn adatom is rather mobile along the trench on GaAs(110), with an energy barrier of 0.56 eV. The energy barrier for segregation across the trenches is nevertheless very high, 1.67 eV. The plots of density of states display a wide gap in the majority spin channel, but show plenty of metal-induced gap states in the minority spin channel. The Mn atoms might be invisibl in scanning tunneling microscope (STM) images taken with small biases, due to the directional p-d hybridization. For example, one will more likely see two bright spots on Mn/GaAs(110), despite the fact that there is only one Mn adatom in the system.