Vibrationally induced flip motion of a hydroxyl dimer on Cu(110)

TL;DR

This paper models vibrationally induced flip motion of a hydroxyl dimer on Cu(110), aligning theoretical predictions with experimental observations through density-functional calculations of vibrational properties.

Contribution

It introduces a model for vibrationally induced switching in nanoscale systems, validated by density-functional calculations and experimental data.

Findings

Calculated population of conductance states matches experiments

Model explains roles of different vibrational modes

Good agreement between theoretical and experimental I-V characteristics

Abstract

Recent low-temperature scanning-tunneling microscopy experiments [T. Kumagai et al., Phys. Rev. B 79, 035423 (2009)] observed the vibrationally induced flip motion of a hydroxyl dimer (OD)2 on Cu(110). We propose a model to describe two-level fluctuations and current-voltage characteristics of nanoscale systems which undergo vibrationally induced switching. The parameters of the model are based on comprehensive density-functional calculations of the system's vibrational properties. For the dimer (OD)2 the calculated population of the high and low conductance states, the I-V, dI/dV, and d2I/dV2 curves are in good agreement with the experimental results and underlines the different roles played by the free and shared OD stretch modes of the dimer.