Structure of self-assembled Mn atom chains on Si(001)

TL;DR

This study reveals that self-assembled Mn atom chains on Si(001) are simpler than previously thought, consisting of single Mn atoms arranged in a necklace-like structure, which accurately explains their asymmetric appearance in STM images.

Contribution

The paper demonstrates that a simple necklace-like chain of single Mn atoms explains the observed features, simplifying previous complex structural models.

Findings

Single Mn atom chains reproduce STM asymmetry

Simpler structural model aligns with experimental data

Enhanced understanding of Mn chain electronic properties

Abstract

Mn has been found to self-assemble into atomic chains running perpendicular to the surface dimer reconstruction on Si(001). They differ from other atomic chains by a striking asymmetric appearance in filled state scanning tunneling microscopy (STM) images. This has prompted complicated structural models involving up to three Mn atoms per chain unit. Combining STM, atomic force microscopy and density functional theory we find that a simple necklace-like chain of single Mn atoms reproduces all their prominent features, including their asymmetry not captured by current models. The upshot is a remarkably simpler structure for modelling the electronic and magnetic properties of Mn atom chains on Si(001).