Effective Models for the Anderson Impurity and the Kondo Model from Continuous Unitary Transformations

Abstract

The method of continuous unitary transformations (CUTs) is applied to the Anderson impurity and the Kondo model aiming at the systematic derivation of convergent effective models. If CUTs are applied in a conventional way, diverging differential equations occur. Similar to poor man's scaling the energy scale, below which the couplings diverge, corresponds to the Kondo temperature $T_K$. We present a way to apply CUTs to the Kondo and to the Anderson impurity model so that no divergences occur but a converged effective low-energy model is derived with small fnite parameters at arbitrarily small energies. The ground state corresponds to a bound singlet with a binding energy given by the Kondo temperature $T_K$.

References in corpus (8)

• The numerical renormalization group method for quantum impurity systems
• A finite-frequency functional RG approach to the single impurity Anderson model
• Systematic Mapping of the Hubbard Model to the Generalized t-J Model
• Effective models for gapped phases of strongly correlated quantum lattice models
• Functional renormalization group approach to the Anderson impurity model
• Spectral function of the Anderson impurity model at finite temperatures
• An alternative functional renormalization group approach to the single impurity Anderson model
• Derivation of the t-J model for finite doping

Cited by in corpus (2)

• In-Medium Similarity Renormalization Group for Closed and Open-Shell Nuclei
• Stable Unitary Integrators for the Numerical Implementation of Continuous Unitary Transformations