Since the 1970s, the question of how to construct effective electronic devices using only a single molecule has attracted significant experimental and theoretical interest. From a theoretical perspective, a key requirement for identifying practical molecular electronic devices is an accurate description of charge transport.<br/><br/>The current standard approach for studying single molecule charge transport problems is the non-equilibrium Green’s function formalism (NEGF) paired with density functional theory (DFT). For some systems though, the conductance and current-voltage curves predicted by common DFT functionals can be several orders of magnitude above experimental results. To address this, I previously introduced a new approximation to the steady-state non-equilibrium Green’s function transport equations. This approximation allows for high accuracy electronic structure methods based on 2-electron reduced density matrix and wavefunction mechanics be applied to steady-state junction transport for the first time.<br/><br/>When studying dithiol alkane chains and dithiol benzene in model junctions, this methodology was found to predict conductance and current values that are 1-2 orders of magnitude below those of common DFT functionals suggesting this approach could be a viable alternative to NEGF-DFT for molecular junction transport. I will discuss new developments to this methodology as well has applications of it to other molecular devices, e.g. biphenyl and biphenyl derivatives, which have been previously shown to function as an ultrafast, nanoscale switches for electrons.

Improved electronic structure methods for molecular junction transport

2019 Spring National Meeting

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