The decoherence of the two- and three-dimensional parabolic quantum dot qubit

On the condition of electric-LO phonon strong coupling in a two- and three-dimensional parabolic quantum dot (QD), we obtain the eigenenergies of the ground state and the first-excited state, the eigenfunctions of the ground state and the first-excited state by using variational method of Pekar type. This system in QD may be employed as a quantum system-qubit. The phonon spontaneous emission causes the decoherence of the qubit. The relations between the decoherence time with the coupling strength, the confinement length, the coefficient dispersion are discussed. (C) 2009 Elsevier B.V. All rights reserved.