2003/12/22 by Tilmann Hickel, T. Hickel, W. Nolting +1
Physics and Astronomy · #Advanced Chemical Physics Studies #Algorithm #Artificial intelligence #Computer science #Database #Diagrammatic reasoning #Physics of Superconductivity and Magnetism #Programming language #Quantum and electron transport phenomena #Variety (cybernetics) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.69.085110
11 pages, 6 figures; accepted by Phys. Rev. B
arxiv created 2003/12/22 · openalex publication_date 2004/02/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The periodic s\ensuremath-d(f) exchange model is characterized by a wide variety of interesting applications, a simple mathematical structure, and a limited number of reliable approximations which take care of the quantum nature of the participating spins. We suggest the use of a projection-operator method for getting information perturbationally, which are not accessible via diagrammatic approaches. In this paper we present, in particular, results beyond perturbation theory, which are obtained such that almost all exactly known limiting cases are incorporated correctly. We discuss a variety of possible methods and evaluate their consequences for one-particle properties. These considerations serve as a guideline for a more effective approach to the model.