Polaron in a Quasi 0D Nanocrystal

Abstract

Polaron states in a spherical quantum dot with a spherical symmetric parabolic confinement potential are investigated applying the Feynman variational principle. Effects of the dot radius on the polaron ground state energy level, the self-action potential energy, the mass and the Fröhlich electron–phonon-coupling constant are obtained for a spherical quantum dot.The electron–phonon-coupling amplitude derived from the Maxwell equation in a material medium is used. This yields a better upper bound for strong coupling polaron energy in a spherical quantum dot.The polaron mass, energy and self-action potential energy are found to have a monotonous decrease as the structures' radius increases. As the spherical quantum dot radius is reduced the regimes of weak and intermediate coupling polaron shorten and the strong coupling polaron region broadens and extends into weak and intermediate ones. The main contribution to polaron energy and mass comes from the self-action potential.