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Spin relaxation rates and effective g-factor of GaAs quantum dots are studied. Both piezoelectric and deformation potentials for acoustic phonons, as well as the intrinsic mixing induced by both Rashba and Dresselhaus spin-orbit couplings, are considered. Influence of different quantum dot parameters is analyzed, and good agreement with experiments is found. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

In this theoretical work we demonstrate that it is possible to use an ac electric field to coherently control the position of an electron in a finite-size quantum-dot array or stack. By tuning the amplitude (or frequency) of the external ac electric field we can selectively suppress the tunneling between dots, trapping the particle in a chosen region of the array. The dynamics is obtained non-perturbatively using Floquet theory and employing a one-band nearest-neighbor tight-biding approximation (NNTB) within the dipole interaction for the external field. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

In this paper we model the effects of applying strong polarized light on a self-assembled single quantum dot photodiode. We use a density matrix formalism where electron and hole tunneling is introduced by rates obtained from a microscopic description. Our analysis shows that elliptical polarized light results in spin-polarized photocurrents, and that sharp polarization reversal can be produced with increasing pulse area. This behavior can be used as a dynamical switch to invert the spin-polarization of the extracted current. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

We study the dynamical behavior of excitations created in a colloidal quantum dot in close proximity to others of similar size. Dipole-dipole interactions result in coherent oscillations of the excitonic population between dots. These can further be monitored via nearby “acceptor” dots that can be probed by time-dependent differential absorption. We present results for a variety of sample materials and realistic structure parameters. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]