Structural Origins of Conductance Fluctuations in Gold-Thiolate Molecular Transport Junctions.

  title={Structural Origins of Conductance Fluctuations in Gold-Thiolate Molecular Transport Junctions.},
  author={William R. French and Christopher R. Iacovella and Ivan Rungger and Amaury de Melo Souza and Stefano Sanvito and Peter T. Cummings},
  journal={The journal of physical chemistry letters},
  volume={4 6},
We report detailed atomistic simulations combined with high-fidelity conductance calculations to probe the structural origins of conductance fluctuations in thermally evolving Au-benzene-1,4-dithiolate-Au junctions. We compare the behavior of structurally ideal junctions (where the electrodes are modeled as flat surfaces) to structurally realistic, experimentally representative junctions resulting from break-junction simulations. The enhanced mobility of metal atoms in structurally realistic… 
29 Citations
Atomistic simulations of highly conductive molecular transport junctions under realistic conditions.
We report state-of-the-art atomistic simulations combined with high-fidelity conductance calculations to probe structure-conductance relationships in Au-benzenedithiolate (BDT)-Au junctions under
Predicting the conductance of strongly correlated molecules: the Kondo effect in perchlorotriphenylmethyl/Au junctions.
A method that combines density functional theory, quantum transport theory, numerical renormalization group (NRG) calculations and renormalized super-perturbation theory (rSPT) to compute both equilibrium and non-equilibrium properties of strongly correlated nanoscale systems at low temperatures effectively from first principles is developed.
Theoretical insights on the importance of anchoring vs molecular geometry in magnetic molecules acting as junctions
Abstract The anchoring of the molecule to an electrode is known to be a key factor in single-molecule spintronics experiments. Likewise, a relaxation down to the most stable geometry is a critical
Interplay between quantum interference and conformational fluctuations in single-molecule break junctions.
It is found that junctions formed from methylsulfide-functionalized trans-α,ω-diphenyloligoene molecules exhibit distinct transport regimes during junction evolution and the signatures of quantum interference in these molecules survive the effect of conformational fluctuations.
Molecular Electronics: Toward the Atomistic Modeling of Conductance Histograms
Reliability in molecular electronics break-junction experiments has come from statistically sampling thousands of repeat measurements. Here we discuss the computational challenges in reproducing the
Unconventional Current Scaling and Edge Effects for Charge Transport through Molecular Clusters
The fundamental differences between single-molecule and ensemble junctions are highlighted, and the scaling of the conductivity of a junction has to be distinctly nonlinear in the number of molecules it contains, to elucidate the collective behavior of parallel molecular wires.
Mapping the details of contact effect of modulated Au-octanedithiol-Au break junction by force-conductance cross-correlation.
This study unravels the relation between force and conductance hidden in the data of a modulated single-molecule break junction system and provides a fresh understanding of electron transport properties at molecule/electrode interfaces.
Stretching of BDT-gold molecular junctions: thiol or thiolate termination?
The results show, for all electrode geometries studied, that the thiol junctions are energetically more stable than their thiolate counterparts, and the conductance of the Au-benzene-1,4-dithiol-Au junctions is overestimated.
Modeling single molecule junction mechanics as a probe of interface bonding
Using the atomic force microscope based break junction approach, applicable to metal point contacts and single molecule junctions, measurements can be repeated thousands of times resulting in rich
Quantitative Interpretations of Break Junction Conductance Histograms in Molecular Electron Transport.
Validation of theoretical and computational tools for extracting quantitative molecular information from experimental conductance histograms for electron transport through single-molecule break junctions shows that background tunneling is crucial for quantitative analyses.


Stochastic modulation in molecular electronic transport junctions: molecular dynamics coupled with charge transport calculations.
The experimental variation in conductance that can be expected through dynamically evolving Au-molecule-Au junctions is approximated using molecular dynamics to model thermal fluctuations and a
Molecular Simulation Studies on the Elongation of Gold Nanowires in Benzenedithiol
The bonding geometry at the metal−molecule interface plays an important role in determining the conductance behavior of metal−molecule−metal junctions. This bonding geometry has to be determined a
Linker dependent bond rupture force measurements in single-molecule junctions.
Despite the strong Au-S bond and the evidence for disruption of the Au structure, the experiments show that on average these junctions also rupture at a smaller force than that measured for pristine single-atom gold contacts.
Oligomeric Gold−Thiolate Units Define the Properties of the Molecular Junction between Gold and Benzene Dithiols
Understanding the structure and conductance of the molecular junction between benzene dithiolates (BDT) and gold electrodes has posed a classic unsolved problem for high-level theoretical work for
Large-scale atomistic simulations of environmental effects on the formation and properties of molecular junctions.
It is demonstrated that tip geometry and monolayer interactions, two factors that are often neglected in simulation, affect the bonding geometry and tilt angle of bridged molecules.
Variability of conductance in molecular junctions.
The geometrical junction to junction variations dominate the conductance measurements, and Histograms constructed from all conductance traces do not show clear peaks either at room or low temperatures.
From tunneling to contact : Inelastic signals in an atomic gold junction from first principles
The evolution of electron conductance in the presence of inelastic effects is studied as an atomic gold contact is formed evolving from a low-conductance regime (tunneling) to a high-conductance
The nature of transport variations in molecular heterojunction electronics.
Transport fluctuations and variations in a series of metal-molecule-metal junctions were quantified through measurements of their thermopower, showing variations are born at the junction formation, increase with molecular length, and are dominated by variations in contact geometry and orbital hybridization, as well as intermolecular interactions.
Effects of self-interaction corrections on the transport properties of phenyl-based molecular junctions
In transport calculations for molecular junctions based on density functional theory the choice of exchange and correlation functional may dramatically affect the results. In particular local and
Ab initio calculations of structural evolution and conductance of benzene-1,4-dithiol on gold leads.
It is concluded that the inclusion of self-interaction corrections is fundamental for describing both the molecule conductance and its stability against conformational fluctuations.