Combined description for semiclassical and quantum transport in superlattices

The de current in strongly coupled superlattices can either be described in a semiclassical picture in terms of miniband transport or in a quantum mec hanical theory based on hopping transitions between the localized wave func tions of the Wannier-Stark ladder. We demonstrate the equivalence of both m odels in the field regime of Bloch-oscillating electrons. Combining these t wo pictures we calculate the superlattice drift velocity resulting from mic roscopic phonon scattering between the Wannier-Stark levels. Our results sh ow that previous discussions of the temperature dependence of the drift vel ocity have to be revised drastically. [S0163-1829(99)05011-0].