Alternative types of molecule-decorated atomic chains in Au-CO-Au single-molecule junctions

TL;DR

This study explores the formation and conductance properties of Au-CO single-molecule junctions, revealing two distinct molecular configurations and their correlations with pure gold atomic chains through statistical and length analyses.

Contribution

It identifies two types of molecule-affected chain formation processes and links experimental observations to theoretical models of molecular configurations.

Findings

Two distinct molecular configurations with different conductance levels.

Strong anticorrelations between molecular configurations and pure gold chains.

Presence of molecular precursor states with higher conductance.

Abstract

We investigate the formation and evolution of Au-CO single-molecule break junctions. The conductance histogram exhibits two distinct molecular configurations, which are further investigated by a combined statistical analysis. According to conditional histogram and correlation analysis these molecular configurations show strong anticorrelations with each other and with pure Au monoatomic junctions and atomic chains. We identify molecular precursor configurations with somewhat higher conductance which are formed prior to single-molecule junctions. According to detailed length analysis two distinct types of molecule-affected chain formation processes are observed, and we compare these results to former theoretical calculations considering bridge and atop type molecular configurations where the latter has reduced conductance due to destructive Fano interference.