ABSTRACT
Charge carriers (electrons, holes, or ions) in multimicron mesoscopic systems behave like particles. Their energies have analog (or classical) character meaning that their energy variables are continuous. However, when one or more of the three Cartesian directions are constrained to a nanometer scale, the carriers exhibit a wave (or quantum) character. In this setup, the energies are digitally (or quantum) separated by forbidden regions. Analog characteristics can be built from digital energies by expanding a nanoscopic system to macro-or microscopic scales in which case the quantum jumps are miniscule. This transformation leads to the concept of density of states (DOS), which is the number of quantum states per unit volume (or area or length) per unit energy.
