ABSTRACT
Bloch electron dynamics in electric ¢elds has been a subject of great interest dating back to the early development of solid-state physics [1-5]. More recently, the availability of band-engineered superlattices (SLs) and tailored periodic structures has stimulated further activities [6-18] in electric ¢eld-mediated transport and optical absorption in low-dimensional SLs and quantum-well (QW) structures, where band gaps and band widths are typically several orders of magnitude smaller than those of bulk solids.
