Dresden 2014 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 74: Correlated Electrons: Quantum Impurities, Kondo Physics
TT 74.10: Vortrag
Mittwoch, 2. April 2014, 17:30–17:45, BEY 81
Local susceptibility and Kondo scaling — Markus Hanl and •Andreas Weichselbaum — Ludwig Maximilians University, Munich
The Kondo scale TK for quantum impurity systems is typically assumed to guarantee universal scaling of physical quantities. In practice, however, not every definition of TK necessarily supports this notion away from the strict scaling limit for finite bandwidth D. Various theoretical definitions of TK are analyzed based on the inverse magnetic impurity susceptibility at zero temperature. While conventional definitions in that respect quickly fail to ensure universal Kondo scaling for all D, an altered definition of TKsc is presented which allows universal scaling of dynamical or thermal quantities for a given fixed Hamiltonian. If the scaling is performed with respect to an external parameter which directly enters the Hamiltonian, such as magnetic field, the corresponding TKsc,B for universal scaling may differ, yet becomes equivalent to TKsc in the scaling limit. The only requirement for universal scaling in the full Kondo parameter regime with a residual error of less than 1% is a well-defined isolated Kondo feature with TK≤ 0.01 D. In particular, by varying D over a wide range relative to the bare energies of the impurity, this allows a smooth transition from the Anderson to the Kondo model.