Superlattice Correlation and Self Energy Phenomena

A quasi-analytical determination of superlattice correlation energy in a normal quantizing magnetic field is carried out at zero temperature. For low magnetic field, both a hydrodynamic model and a quantum mechanical RPA (random phase approximation) model of nonlocal dynamic dielectric properties are employed in the evaluation of the monotonic magnetic field dependence of the correlation energy. Intermediate magnetic field strength de Haas-van Alphen (DHVA) oscillatory corrections are calculated in closed form as a perturbation. The quantum strong field limit in which only the lowest Landau state is populated is also analyzed. The role of the magnetic field in correlation energy is examined for both closely-packed and loosely -packed superlattices. In addition, the effects of finite thickness of superlattice sheets are treated in the lowest subband approximation in our correlation energy calculations. Furthermore, we set up the formulation for calculation of superlattice self energy for zero thickness sheets as well as finite thickness in the lowest subband approximation, employing the shielded potential approximation.