ABSTRACT
In this chapter, we will describe the electronic transport properties of a particular type of mesoscopic structure, namely, point contacts with lateral dimensions of a single or a few atoms. ese structures, rst realized in the early 1990s, are still attracting much interest because they represent test beds for important concepts of quantum mechanics, quantum chemistry, atomic physics, and solid-state physics. While the rst years of research were devoted to the understanding of the intrinsic transport properties of atomic-size contacts (APCs) of normal metals, new elds of interest have now been entered, for example, the application of APCs to provide highly-spin polarized resistors or atomically sharp electrodes for contacting individual nanoobjects in the context of molecular electronics.
