Physics of electronic transport in single atoms, molecules and related nanostructures

Abstract

The idea of electronic transport in molecular-scale systems dates back to the original theoretical proposals of the 1970s of unimolecular transport, and over the last decade has gained experimental verification by the realization in a variety of systems. The special section in this issue of Nanotechnology surveys the progress in this rapidly evolving field of molecular and atomic scale electronic transport.The paper by Datta (page S433) discusses the theoretical basis of electronic conductance from an atomistic point of view, and presents the methods and challenges to developing a full predictive theory of these systems. The paper by Di Ventra et al (page S459) elaborates on this, presenting theoretical results on shot noise in these types of systems. A nice comparison of these studies with experimental results is presented by Schönenberger et al (page S479).Experimental papers are presented in a number of diverse systems in this regime. In the field of organic and molecular transport, Hersam et al (page S452) present results of scanning tunnelling spectroscopy of organic monolayers, and Kushmerick et al (page S489) present results on molecular junction transport and rectification. To test theoretical models of molecular transport, Mayer et al (page S483) present thermal activation studies of molecular junctions.A valuable tool for the study of molecular and atomic transport is the mechanically controllable break junction, presented in two papers here. The work by van Ruitenbeek et al (page S472) presents results on atomic chains of atoms, and Scheer et al (S465) present a study of this technique for measuring molecular junctions.The tremendous progress seen within the last decade in this nascent field bodes well for the understanding of molecular scale electronic systems. The papers presented here, written by leading experts in the field, introduce some of the most important breakthroughs in molecular nanoelectronic technologies under development today.