Search

The spin-flip scattering mechanism in coupled self-assembled quantum dots made with InAs/GaAs with the use of realistic material parameters is theoretically and numerically investigated. The electron wave functions within the coupled system have been calculated by the 8-band strain dependent [Formula: see text] theory. The phonon coupling to electrons is described by deformation potential and piezoelectric acoustic phonons. First order perturbation theory has been employed to evaluate the spin relaxation rates and spin-flip time T1. The numerical results show that parameters like the interdot distance and the applied static magnetic field are of crucial importance in spin-flip mechanism. The spin relaxation time has been also studied by varying the lattice temperature and by showing the differences between the quantum computing operation temperature ([Formula: see text] K) and large temperatures.

Detailed realistic calculations of the spin-flip time (T 1 ) for an electron in a self-assembled quantum dot (SAQD) due to emission of an acoustic phonon, using only bulk properties with no fitting parameters, are presented. Ellipsoidal lens shaped [Formula: see text] [Formula: see text]As quantum dots, with electronic states calculated using 8-band strain dependent [Formula: see text] theory, are considered. The phonons are treated as bulk acoustic phonons coupled to the electron by both deformation potential and piezoelectric interactions. The dependence of T 1 on the geometry of SAQD, on the applied external magnetic field and on the lattice temperature is highlighted. The theoretical results are close to the experimental measurements on the spin-flip times for a single electron in QD.

An external magnetic field has been applied in laterally coupled quantum dots (QDs) and we have studied the QD properties related to charge decoherence. The significance of the applied magnetic field to the suppression of electron-phonon relaxation and dephasing rates has been explored. The coupled QDs have been studied by varying the magnetic field and the interdot distance as well as other system parameters. Our numerical results show that the electron scattering rates are strongly dependent on the applied external magnetic field and the details of the double QD configuration.