Eur. Phys. J. B 33, 153-164 (2003)
https://doi.org/10.1140/epjb/e2003-00152-1

Collective electronic excitations in a semiconductor superlattice in the Landau and Wannier-Stark ladder regime

¹ Department of Physics, N.P. Ogarev Mordovian State University, Saransk 430000, Russia
² Department of Informatics and Computer Science, Mordovian State Pedagogical Institute, Saransk 430007, Russia
³ Department of Chemistry, N.P. Ogarev Mordovian State University, Saransk 430000, Russia

Corresponding author: ^a 612033@inbox.ru

Received: 29 August 2002
Revised: 25 February 2003
Published online: 4 June 2003

Abstract

Using a mean-field approximation, we have developed a systematic treatment of collective electronic modes in a semiconductor superlattice (SL) in the presence of strong electric and magnetic fields parallel to the SL axis. The spectrum of collective modes with zero wavevector along the SL axis is shown to consist of a principle magnetoplasmon mode and an infinite set of Bernstein-like modes. For non-zero wavevector along the SL axis, in addition to the cyclotron modes, extra collective modes are found at the frequencies , which we call cyclotron-Stark modes ( and are respectively the cyclotron and Stark frequencies, N and M are integer numbers). The frequencies of the modes propagating in “oblique” direction with respect to the SL axis show oscillatory behavior as a function of electric field strength. All the modes considered have very weak spatial dispersion and they are not Landau damped. The specific predictions made for the dispersion relations of the collective excitations should be observable in resonant Raman scattering experiments.