Recursive computation of matrix elements in the numerical renormalization group

摘要: The numerical renormalization group is an efficient method to diagonalize model Hamiltonians describing correlated orbitals coupled conduction states. While only the resulting eigenvalues are needed calculate thermodynamical properties for such models, matrix elements of Fermi operators must be evaluated before excitation and transport can computed. traditional procedure typically as expensive diagonalization Hamiltonian. Here, we present a substantially faster alternative that demands much less memory, yields equally accurate easier code.