The merging of the concept of introduction of asymmetry of the wave
vector space of the charge carriers in semiconductors with the modern
techniques of fabric- ing nanostructured materials such as MBE, MOCVD,
and FLL in one, two, and three dimensions (such as ultrathin ?lms, nipi
structures, inversion and accumu- tion layers, quantum well
superlattices, carbon nanotubes, quantum wires, quantum wire
superlattices, quantumdots, magnetoinversionand accumulationlayers, qu-
tum dot superlattices, etc. ) spawns not only useful quantum effect
devices but also unearth new concepts in the realm of nanostructured
materials science and related disciplines. It is worth remaking that
these semiconductor nanostructures occupy a paramount position in the
entire arena of low-dimensional science and technology by their own
right and ?nd extensive applications in quantum registers, resonant
tunneling diodes and transistors, quantum switches, quantum sensors,
quantum logic gates, heterojunction ?eld-effect, quantum well and
quantum wire trans- tors, high-speed digital networks, high-frequency
microwave circuits, quantum cascade lasers, high-resolution terahertz
spectroscopy, superlattice photo-oscillator, advanced integrated
circuits, superlattice photocathodes, thermoelectric devices,
superlattice coolers, thin ?lm transistors, intermediate-band solar
cells, micro- tical systems, high-performanceinfrared imaging systems,
bandpass ?lters, thermal sensors, optical modulators, optical switching
systems, single electron/molecule electronics, nanotube based diodes,
and other nanoelectronic devices.