Lieb lattices formed by real atoms on Ag(111) and their lattice constant dependent electronic properties

TL;DR

This study constructs Lieb lattices using Fe atoms on Ag(111) to investigate their electronic properties, revealing unexpected long-range electron wavefunction overlap facilitated by surface states, with implications for designing atomic-scale devices.

Contribution

It demonstrates the formation of Lieb lattices with real atoms and uncovers long-range electron overlap mechanisms not predicted by traditional models.

Findings

Long-range 1/r2 electron wavefunction overlap observed

Surface state enables extended electronic interactions

Provides a platform for designing atomic-scale electronic structures

Abstract

Scanning tunneling microscopy is a powerful tool to build artificial atomic structures even not exist in nature but possess exotic properties. We here constructed Lieb lattices with different lattice constants by real atoms, i.e., Fe atoms on Ag(111) and probed their electronic properties. We find a surprising long-range effective electron wavefunction overlap between Fe adatoms as it exhibits a 1/r2-dependence with the interatomic distance r instead of the theoretically predicted exponential one. Combining control experiments, tight-binding and Green's function calculations, we attribute the observed long-range overlap to be enabled by the surface state. Our findings not only enrich the understanding of the electron wavefunction overlap, but also provide a convenient platform to design and explore the artificial structures and future devices with real atoms.