Electron correlations in mesoscopic structures

Ultra-small electronic systems on the 10-1000 Å length scale are called ‘mesoscopic’ systems with properties lying between the microscopic quantum-mechanical world of atoms and the macroscopic, largely classical world of present-day electronic devices. Mesoscopic systems can either occur naturally or be artificially fabricated and can perhaps be used as high-speed optoelectronic devices. Of specific interest in the field of condensed-matter physics is the semiconductor ‘quantum dot’ which can contain fewer than ten electrons; its study opens up the fascinating world of few-body physics in the traditionally many-body field of condensed matter. Here I discuss some of the electron correlation effects that arise in such quantum dot systems.