A.Kh. Manaselyan

Effect of a magnetic impurity on the optical properties of a spherical ZnSe quantum dot

We consider the electron and hole states in a semiconductor ZnSe spherical quantum dot, in the center of which a magnetic impurity atom of manganese is located. In calculations the quantum dot is approximated by a spherical rectangular well with a finite depth. Within the framework of perturbation theory, the effect of exchange spin interaction of an electron and a hole with a magnetic impurity on the band structure of the system is considered. The optical spectrum of the system for different polarizations of the incident light is studied also.

Intersubband absorption in quantum wire with a convex bottom in a magnetic field

The electron states in a cylindrical quantum well with a convex bottom in a magnetic field directed along the wire axis are investigated. The electron wavefunctions, depending on the quantum well characteristics and the magnetic field induction, are found. The absorption coefficient of a monochromatic linearly polarized light wave caused by intersubband transitions of electrons in the quantum wire is calculated. The selection rules are considered and analytical expressions for the absorption coefficient are presented for two cases of light wave polarization.

Spin interactions in a quantum ring containing a magnetic impurity

The exciton states in a CdTe semiconductor quantum ring containing a single magnetic impurity are considered in an external magnetic field. The electron-hole spin interaction and s,p-d interactions between electron, hole and magnetic impurity are also taken into account in the calculations. It is shown that due to the s,p-d spin interactions the ground state exciton energy splits into 12 doubly degenerated energy levels. The external magnetic field removes this degeneracy. A novel method is proposed here to determine the values of the strengths of s,p-d interactions. The optical spectrum of the system for different polarizations of the incident light and for different initial states of the magnetic impurity spin projection is also studied.

Electronic States in the Valence Band of a Cylindrical ZnSe Quantum Dot

Electronic states in the valence band of a cylindrical ZnSe quantum dot are studied with allowance for the valence band mixing. Dependences of the wave functions and energy levels on the quantum dot radius are calculated. The influence of a magnetic field parallel to the quantum dot radius on the energy levels is also considered.

Mobility of charge carriers with position-dependent effective mass in a quantum film

The scattering of electrons on charged impurity centers in a quantum film with the parabolic confining potential is investigated, taking into account the coordinate dependence of the electron effective mass in the film. The mobility is calculated for various distributions of impurity centers (homogeneous distribution in the film, barrier region, and the whole space). It is shown that the consideration of the coordinate dependence leads to the mobility decrease.