Probing electronic excitations in molecular conduction

Abstract

We identify experimental signatures in the current-voltage (I-V) characteristics of weakly contacted molecules directly arising from excitations in their many electron spectrum. The current is calculated using a multielectron master equation in the Fock space of an exact diagonalized model many-body Hamiltonian for a prototypical molecule. Using this approach, we explain several nontrivial features in frequently observed I-Vs in terms of a rich spectrum of excitations that may be hard to describe adequately with standard one-electron self-consistent field (SCF) theories.

Significantly different content -- inadequacy of SCF approach described with simple model, and a whole new class of experiments showing gate modulated current steps discussed in terms of excitations in the molecular many-body space