My current research focuses on the investigation of a host of nanoscale systems. Specifically, my work in the Cummings and McCabe groups focuses on (1) the simulation of nanowires and molecular junctions for nano- and molecular-electronics applications, (2) simulation and free energy calculations of nanoconfined fluids, (3) simulation of the phase behavior of grafted nanoparticles, (4) synthesis mimetic simulation of self-assembled monolayers, and (5) simulation and development of atomistic and coarse-grained models for the investigation of ceramide bilayer systems. My past graduate research focused on the simulation of the self-assembly of amphiphilic tethered nanoparticles into ordered crystalline and quasicrystalline structures, as well as the simulation and modeling micron-sized colloidal particles in direct collaboration with experiment. My current and past work includes a particular focus on the development and application of flexible order parameters based o
n shape matching.
Structure and Properties of Mechanically Deformed Nanowires and Molecular junctions:
Nano- and molecular-electronics systems, i.e., self-assembled electronic systems composed of atomic-scale contacts or single-molecules, hold significant promise for the creation of ultra dense, ultra fast electronic components. Understanding the correlations between structure and conductance is an important step towards the future design of future electronic devices.
In our work, we employ a combination of “classical” forcefields (both semi-emperical and reactive), shape matching order parameters, and density functional theory (DFT) conductance calculations to investigate the structure/property relationships in mechanical deformation of Au nanowires and the formation of molecular junctions composed of 1,4 benzene dithiol (BDT). Our approach to the problem is unique, in that we capture the entire process of junction formation, allowing the junctions to form naturally rather than starting from assumed, idealized starting configurations. Additionally, our approach enables us to capture thermal, environmental, and stochastic effects that would be present in experiment.
- French WR, Pervaje A, Santos A, Iacovella CR, Cummings PT, GPU-Enabled Large-Scale Statistical Study of Size-Dependent Failure in Elongating Gold Nanowires, submitted
- French WR, Iacovella CR, Rungger I, Souza A, Sanvito S, Cummings PT (2013) Atomistic Simulations of Highly Conductive Molecular Transport Junctions Under Realistic Conditions, Nanoscale, 5 pp 3654-3659
–DOI:10.1039/C3NR00459G (open access): arXiv:1303.5036
- French WR, Iacovella CR, Rungger I, Souza A, Sanvito S, Cummings PT (2013) Structural Origins of Conductance Fluctuations in Gold-Thiolate Molecular Transport Junctions , Journal of Physical Chemistry Letters, 4 pp 887–891
- French WR, Iacovella CR, Cummings PT (2012) Large-Scale Atomistic Simulations of Environmental Effects on the Formation and Properties of Molecular Junctions, ACS Nano, 6, pp 2779–2789
– DOI:10.1021/nn300276m : arXiv:1202.3380
- Iacovella CR, French WR, Cook BG, Kent PRC, Cummings PT (2011) Role of Polytetrahedral Structures in the Elongation and Rupture of Gold Nanowires, ACS Nano, 5, pp 10065–10073
– DOI:10.1021/nn203941r : arXiv:1110.6396v1
- French WR, Iacovella CR, Cummings PT (2011) The Influence of Molecular Adsorption on Elongating Gold Nanowires, Journal of Physical Chemistry C, 115 pp 18422–18433
– DOI:10.1021/jp203837r : arXiv:1108.6251v1
- Iacovella CR, French WR, Cummings PT (2011) Flexible order parameters for quantifying the rate-dependent energy release mechanism of Au nanowires, Proceedings of SciDAC 2011, Denver, CO, July 10-14