Probing electronic excitations in molecular conduction

Bhaskaran Muralidharan, School of Electrical and Computer Engineering, Network for Computational Nanotechnology, Purdue University
A. W. Ghosh, School of Electrical and Computer Engineering, University of Virginia
Supriyo Datta, Network for Computational Nanotechnology, Birck Nanotechnology Center, Purdue University

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 theories.