Sub-femtosecond Electron Transport in Nanoscale Junctions

Sub-femtosecond Electron Transport in Nanoscale Junctions

Markus Ludwig
Department of Physics
University of Konstanz
Germany

We harness phase-locked 4.2-femtosecond single-cycle transients at a pikojoule-level for sub-femtosecond all-optical biasing of a nanoscale tunneling junction embedded into a plasmonic nanocircuit. The resulting tunneling current bursts can be fully controlled by the carrier-envelope phase of the driving field and operate on attosecond time scales in a few-electron regime. By means of optical characteristic curves and interferometric autocorrelations we can probe the underlying ultrafast dynamics. Recently we advanced our studies towards atomic-scale tunneling junctions where electronic transport occurs between two individual gold atoms and thus through a single conduction channel. Such experiments provide access to quantum transport phenomena confined to truly atomic time and length scales.