Semi-analytical solution of the Kondo model in a magnetic field

Abstract

The single impurity Kondo model at zero temperature in a magnetic field is solved by a semi-analytical approach based on the flow equation method. The resulting problem is shown to be equivalent to a resonant level model with a non-constant hybridization function. This nontrivial effective hybridization function encodes the quasiparticle interaction in the Kondo limit, while the magnetic field enters as the impurity orbital energy. The evaluation of static and dynamic quantities of the strong-coupling Kondo model becomes very simple in this effective model. We present results for thermodynamic quantities and the dynamical spin-structure factor and compare them with NRG calculations.

arXiv comment7 pages, 5 figures; revised version contains additional references, corrected Fig. 4 and discussion of Wilson ratio

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Cited by in corpus (7)

• Universal Resistances of the Quantum RC circuit
• Functional renormalization group approach to zero-dimensional interacting systems
• Crossover from Non-Equilibrium to Equilibrium Behavior in the Time-Dependent Kondo Model
• Quantum phase transition of Ising-coupled Kondo impurities
• Flow Equations and Normal Ordering. A Survey
• Universal asymptotic behavior in flow equations of dissipative systems
• Effective Models for the Anderson Impurity and the Kondo Model from Continuous Unitary Transformations