Electronic Transport in Thin Film Nanostructures

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

The primary objective of the proposed research is the investigation of quantum electrical transport in thin film nanostructures on silicon substrates. The project focuses on atomic-wire arrays and on atomically smooth metal films. Under certain growth conditions, individual metal atoms "self-assemble" into macroscopic domains of parallel "atom wires" with equal but tunable spacing between the wires. These arrays are ideal for studying the fundamentals of quantum electrical transport a function of system dimensionality and Fermi surface topology using nanoscopic probes such as a four-tip Scanning Tunneling Microscope, as well as macroscopic measurement probes such as electron- or laser beams. Atomically smooth metal films will be synthesized via a novel self-assembly mechanism that is driven by the quantum-size effect, which allows for a systematic investigation of the conductivity in relation to quantum interference, quantum confinement, and classical size effects. These studies will allow researchers to extract the key characteristics that are relevant for the operation of future nanoscale devices. The proposed science and supporting infrastructure at The University of Tennessee and nearby Center for Nanophase Materials Sciences provide an excellent setting for the education and training of internationally competitive students and postdocs. These young people will take their place in the highly skilled workforce that will continue to drive innovation and prosperity in today's high-tech society. Quantum electrical transport is at the heart of nanoscience. The idea of assembling single atoms or molecules and small chemical groups into much faster and powerful electronic devices no longer belongs to the realm of science fiction. Recently, researchers wired up their first molecular-scale electronic circuits, an achievement Science Magazine selected as the "Breakthrough of 2001". Researchers now face the daunting task of taking this new technology from basic electronic components to complex integrated circuits that can rival silicon's low cost performance and reliability. Reaching that level of complexity requires several scientific breakthroughs besides the obviously needed revolution in chip fabrication and design. In this project, researchers will align individual metal atoms into "atomic wires" or arrange the atoms into a perfectly smooth film that is only a few atom layers thick. These nanostructured materials are ideal model systems that will allow researchers to explore the fundamentals and key characteristics of electrical currents in nanophase materials. Quantum transport marries the most fundamental laws of nature, namely quantum mechanics, with applied electrical engineering and emerging materials technologies. The proposed science and supporting infrastructure at The University of Tennessee and the nearby Center for Nanophase Materials Sciences of the Department of Energy provide an excellent setting for the education and training of internationally competitive students and postdocs using specialized national research facilities. These young people will take their place in the highly skilled workforce that will continue to drive innovation and prosperity in today's high-tech society.