Conductivity of an atomically defined metallic interface

David J. Oliver, McGill University
Jesse Maassen, McGill University; Birck Nanotechnology Center, Purdue University
Mehdi El Ouali, McGill University
William Paul, McGill University
Till Hagedorn, McGill University
Yoichi Miyahara, McGill University
Yue Qi, Gen Motors R&D Ctr
Hong Guo, McGill University
Peter Gruetter, McGill University

Date of this Version



PNAS, Vol. 109, No. 47


Copyright (2013) National Academy of Sciences. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the National Academy of Sciences. The following article appeared in PNAS vol. 109 no. 47 and may be found at http// The following article has been submitted to/accepted by Proceedings of the National Academy of Sciences. Copyright (2013) David J. Oliver, Jesse Maassen, Mehdi El Ouali, William Paul, Till Hagedorna, Yoichi Miyahara, Yue Qic, Hong Guo, and Peter Grütter. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


A mechanically formed electrical nanocontact between gold and tungsten is a prototypical junction between metals with dissimilar electronic structure. Through atomically characterized nanoindentation experiments and first-principles quantum transport calculations, we find that the ballistic conduction across this intermetallic interface is drastically reduced because of the fundamental mismatch between swave-likemodes of electron conduction in the gold and d wave-like modes in the tungsten. The mechanical formation of the junction introduces defects and disorder, which act as an additional source of conduction losses and increase junction resistance by up to an order of magnitude. These findings apply to nanoelectronics and semiconductor device design. The technique that we use is very broadly applicable to molecular electronics, nanoscale contact mechanics, and scanning tunneling microscopy.


Nanoscience and Nanotechnology