2006/10/31 by Christian Kolf, Johann Kroha · 1 citation
Chemistry · Physics and Astronomy · #Advanced NMR Techniques and Applications #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.75.045129
published as Phys. Rev. B 75, 045129 (2007) · 6 pages, 3 figures; PRB published version, shortened, nomenclature clarified
arxiv created 2006/12/21 · openalex publication_date 2007/01/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We perform numerical renormalization group (NRG) as well as analytical calculations for the two-channel Kondo (2CK) model to obtain the dependence of the Kondo temperature TK on the dimensionless (bare) spin exchange coupling g over the complete parameter range from g⪡1 to g⪢1. We show that there exists a duality between the regimes of small and large coupling. It is unique for the two-channel model and enables a mapping between the strong and the weak coupling cases via the identification g\ensuremath↔3∕(2g), implying an exponential dependence of TK on 1∕g and g, respectively, in the two regimes. This agrees quantitatively with our NRG calculations where we extract TK(g) over the complete parameter range and obtain a nonmonotonic TK(g) dependence, strongly peaked at the 2CK fixed point coupling g*. These results may be relevant for resolving the long-standing puzzle within the 2CK interpretation of certain random defect systems as to why no broad distribution of TK is observed in those systems.