A. G. Panfilov

Optical Selection Rules for Hexagonal GaN

We determined the possible symmetries for band (Bloch) states at various points of the Brillouin zone. The spin–orbit interaction has been taken into account. Free excitons offer larger sets of possible state symmetries than single carriers do. The selection rules for the optical transitions have been established. Experiments with polarized light are shown to be relevant to study the nature (s or p) of A, B, and C excitons.

Electron state symmetries and optical transitions in semiconductor superlattices: II. grown along the [110] and [111] directions

Using the method of induced band representations of space groups, we have performed a complete group-theory analysis of electron state symmetries in superlattices grown along the [110] and [111] directions. The spin - orbit interaction has been taken into account. The formulae giving, for arbitrary numbers of monolayers m and n, the arrangements of atoms over the Wyckoff positions have been obtained. The selection rules for both direct and phonon-assisted optical transitions have been derived. Using results of the group-theory analysis, we predict some variations in the optical transitions when m and/or n are varied. We also propose polarized-light optical experiments to establish the detailed electron-band structures of the superlattices.

Electron State Symmetries and Optical Selection Rules in the (GaAs)m(AlAs)n Superlattices Grown along the [001], [110], and [111] Directions

Recently, using the method of induced band representations of space groups, the full electron state symmetries and the selection rules for optical transitions in the (GaAs)m(AlAs)n superlattices (SL’s) were studied. The [001], [110], and [111] growth directions have been considered [1,2]. Below, we give a review of the group-theory method used and the main results obtained.

Quasi two dimensionality of phonon subsystems of perovskite-like high-Tc superconductors

Abstract The results of group-theory analysis, lattice dynamical calculations, and experimental data on the vibrational spectra of perovskite-like HTSC are considered together. A conclusion on quasi-2D nature of the phonon subsystems is made.