QUANTUM TRANSPORT IN MICROSTRUCTURES Daniel

Advanced microfabrication techniques allow production of experimental systems as narrow as 20 nm for study of electron transport at low temperatures, ~IK. Fine wires in metals, Si-MOS inversion layers, and GaAs modulation-doped heterostructure layers have been studied. Metal rings of diameter ~I ~m have also been studied. New electron interference effects have been discovered in these systems, due to electron partial waves which scatter elastically from impurities. The length scale over which these interference effects occur is the phase coherence length, ~, of order I ~m or greater at IK. In this paper the physical mechanisms and manifestations of these electron interference effects are reviewed. The microfabrication methods used to produce these ultrasmall structures are also reviewed. Other quantum transport issues, including inelastic scattering mechanisms, detection of single trap states, and wavefunction spatial quantization, are also discussed.