This book collects papers on the fundamentals and applications of nanoscale devices, first presented at the NATO Advanced Research Workshop on Nanoscale Devices - Fundamentals and Applications held in Kishinev, Moldova, in September 2004. The focus is on the synthesis and characterization of nanoscale magnetic materials; fundamental physics and materials aspects of solid-state nanostructures; development of novel device concepts and design principles for nanoscale devices; and on applications in electronics with emphasis on defence against the threat of terrorism.