Density functional theory of normal and superconducting electron liquids: explicit functionals via the gradient expansion

摘要: The basic idea of density functional theory is to map an interacting many-particle system on effective non-interacting in such a way that the ground-state densities two systems are identical. particles move local potential which density. central task find good approximations for dependence this single-particle potential. An overview recent advances construction (beyond local-density approximation) will be given along with successful applications quantum chemistry and solid state theory. We then turn extension superconductors first discuss Hohenberg-Kohn-Sham-type existence theorems. In superconducting analogue normal-state Kohn-Sham formalism, needed now depends densities, ordinary n(r) anomalous △(r,r/). As step towards potential, gradient expansion technique presented applied calculate approximation kinetic energy Ts[n, △]. also obtain Thomas-Fermi-type variational equation superconductors.