Eur. Phys. J. B 35, 443-447 (2003)
https://doi.org/10.1140/epjb/e2003-00297-9

Electron velocity in superlattices

¹ Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000 Ljubljana, Slovenia
² Institut für Festkörperelektronik, Technische Universität Wien, Florag. 7, 1040 Wien, Austria

Corresponding author: ^a Uros.Merc@fe.uni-lj.si

Received: 17 April 2003
Revised: 7 August 2003
Published online: 24 October 2003

Abstract

Calculations of the electron velocity in superlattices based on the miniband dispersion relation, and the velocity defined through the tunneling time are discussed. The former definition is based on the intrinsically infinite modified Kronig-Penney model, while the latter rests upon the transfer matrix method and takes the finiteness of the superlattice into account. The main result is that the velocities differ: for weakly coupled structures where the tunneling time can be defined through the linewidth, the transfer matrix method predicts a smaller velocity than the modified Kronig-Penney model.