The Decoherence of the Unsymmetrical Parabolic Confinement Potential Quantum Dot Qubit

On the condition of electric-LO phononstrong coupling in unsymmetrical parabolic confinementpotential Quantum dot (QD), we obtain the eigenenergiesof the ground state and the first-excited state, the eigenfuctions of the ground state and the first-excited state byusing variational method of Pekar type. This system inQD may be employed as a two-level quantum systemqubit.The phonon spontaneous emission causes the decoherenceof the qubit. The relations between decoherence time withthe coupling strength, the confinement strengths in thexy-plane and the z direction, the coeffcient dispersion arediscussed.