Spatially modulated interface states in a two-dimensional potential: Single-layer RbI on Ag(111)

Benjamin W McDowell; Jon M Mills; Motoaki Honda; George V Nazin

doi:10.1063/5.0177126

Spatially modulated interface states in a two-dimensional potential: Single-layer RbI on Ag(111)

J Chem Phys. 2023 Dec 14;159(22):224705. doi: 10.1063/5.0177126.

Authors

Benjamin W McDowell¹, Jon M Mills¹, Motoaki Honda¹, George V Nazin¹

Affiliation

¹ Department of Chemistry and Biochemistry, Materials Science Institute, Oregon Center for Optical, Molecular, and Quantum Science, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA.

PMID: 38078526
DOI: 10.1063/5.0177126

Abstract

Alkali halides are known to exhibit interface electronic states (IES) when deposited on metal surfaces with ultra-thin coverage. Here, we examine the IES formed by sub-monolayer RbI growth on Ag(111), which exhibits spatial variations in electronic structure in surprising contrast to the results previously obtained for other alkali halides. We find that this spatially dependent behavior can be qualitatively modeled by using a two-dimensional cosine potential commensurate with the moiré superstructure, where the IES is constructed from the well-known analytical solutions to the Mathieu equation. Our results indicate this potential is more corrugated than for similar potentials reported for other alkali halides, a result of substrate-adlayer charge transfer interactions that are stronger for RbI. This two-dimensional effective potential leads to anisotropy in the effective electron mass, in surprising contrast to previous results for other alkali halides, which report a single isotropic mass.