Renormalization approach to many-particle systems

Article

关键词: FLOW-EQUATIONS;    HAMILTONIANS;   

DOI  :  10.1103/PhysRevB.66.235115

来源: SCIE

【 摘 要 】

This paper presents a renormalization approach to many-particle systems. By starting from a bare Hamiltonian H=H-0+H-1 with an unperturbed part H-0 and a perturbation H-1, we define an effective Hamiltonian which has a band-diagonal shape with respect to the eigenbasis of H-0. This means that all transition matrix elements are suppressed which have energy differences larger than a given cutoff lambda that is smaller than the cutoff Lambda of the original Hamiltonian. This property resembles a recent flow equation approach on the basis of continuous unitary transformations. For demonstration of the method we discuss an exact solvable model, as well as the Anderson-lattice model where the well-known quasiparticle behavior of heavy fermions is derived.

【 授权许可】

Free