Influences of dispersion, dielectric constant and polarization on the double-parameter asymmetric Gaussian potential quantum dot qubit

Abstract

Selecting the double-parameter asymmetric Gaussian (AG) potential to describe the confinement effects of electrons in quantum dot (QD), the effect of dielectric constant, dispersion and polarization on the properties of the QD qubit is studied by LLP–Pekar transformation variation method. By discussing the oscillation period of the qubit with the AG potential, the mechanism of influence of the material parameters such as the dielectric constant ratio and the electron–phonon coupling (EPC) constant on qubit survival time and information storage is clarified. Based on the Fermi gold rule and the even-order approximation, the qubit decoherence with AG potential is studied. It is revealed that increasing the dielectric constant ratio, the dispersion or the EPC constant of materials is all ways to solve the qubit decoherence due to spontaneous emission of phonons. The theoretical basis for phase rotation control of qubit spheres is given by improving dispersion coefficient or dielectric constant ratio of materials.