The aim of this work is to describe the behavior of a device capable to generate high frequency (~THz) acoustic phonons. This device consists in a GaAs-AlGaAs double barrier heterostructure that, when an external bias is applied, produces a high rate of longitudinal optical LO phonons. These LO phonons are confined and they decay by stimulated emission of a pair of secondary longitudinal optical (LO_2) and transversal acoustic (TA) phonons. The last ones form an intense beam of coherent acoustic phonons. To study this effect, we start from a tight binding Hamiltonian that take into account the electron-phonon (e-ph) and phonon-phonon (ph-ph) interactions. We calculate the electronic current through the double barrier and we obtain a set of five coupled kinetic equations that describes the electron and phonon populations. The results obtained here confirm the behavior of the terahertz phonon laser, estimated by rougher treatments.
@article{arxiv.cond-mat/0101043,
title = {The terahertz phonon laser: a full quantum treatment},
author = {I. Camps and S. S. Makler and H. M. Pastawski and L. E. F. Foa Torres},
journal= {arXiv preprint arXiv:cond-mat/0101043},
year = {2007}
}
Comments
8 figures, submitted for publication in Physical Review B