Itinerant Electron Magnets: Curie Temperature and Susceptibility in Density-Functional Theory

摘要: Groundstate properties of solids are astonishingly well described by the local density functional approximation (LDA) [1]. This is also true metallic magnets for which situation was recently this author [2]. Excited-state (and other systems), however, still a great challenge and it believed until that band-picture, based in LDA, fails entirely describing magnetism at elevated temperatures. We emphasize here not so, attempting first to expose reason why thought band-picture fails. Since historically underlying physical picture developed Stoner Wohlfarth, we begin with discussion their theory using, an approach reveals essential assumptions. Mermin’s [3] finite-temperature theory. Two points emerge: one noncollinearity magnetic moments finite temperatures, form exchange-correlation contribution thermodynamic potential. know how deal noncollinear order LDA explain might use knowledge advance issue. Exchange correlation temperatures are, present state understood. statement only applies but many-body treatments addressed workshop.