Dynamical phonon-induced dephasing of an optically controlled single spin in a quantum dot

Abstract

We study the dephasing mechanism due to carrier-phonon interaction of an operation on a single spin in a quantum dot performed by optical means. We calculate the total error of the spin-based quantum gate taking into account the influence of the carrier coupling to the phonon and photon fields as well as the imperfections of the unitary evolution such as off-resonant excitations and the nonadiabaticity of the driving. We give quantitative estimation for a π rotation of a spin in two types of quantum dots: self-assembled InAs/GaAs and fluctuation GaAs quantum dots, and discuss the different interplay of the constituent sources of the errors.