The decoherence time of anisotropic quantum dot qubit: Effects of electric field, electron–phonon interactions, and impurities

Abstract

In the field of quantum computation , one of the key issues is how to prolong the decoherence time of qubits. In the present work, the decoherence time is calculated in the framework of the Landau-Pekar variational approach for an anisotropic quantum dot (QD) under external electric fields including electron–phonon interactions. We obtained the parameterized eigenenergies of the ground state (GS) and the first excited-state (ES) by constructing the electronic wave functions for the GS and the first ES. We demonstrate that the calculation can explain consistently the dependence of decoherence time on the electric field strength, longitudinal-optical phonons and impurities. Our results should be useful for experimental investigation of QD qubit. • This paper studied investigated decoherence time of anisotropic quantum dot qubit. • A Landau-Pekar method is employed to obtain the GS and first ES energies. • An analysis of how the decoherence time depend on the electric field is presented. • We plotted the parameter phase diagram between the confinement length in the z-direction and the electric field strength.