Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10713968 | Physica B: Condensed Matter | 2012 | 4 Pages |
Abstract
Motivated by experiments in nanoscopic systems, we study a generalized Anderson, which consist of two spin degenerate doublets hybridized to a singlet by the promotion of an electron to two conduction bands, as a function of the energy separation δ between both doublets. For δ=0 or very large, the model is equivalent to a one-level SU(N) Anderson model, with N=4 and 2 respectively. We study the evolution of the spectral density for both doublets (Ï1Ï(Ï) and Ï2Ï(Ï)) and their width in the Kondo limit as δ is varied, using the non-crossing approximation (NCA). As δ increases, the peak at the Fermi energy in the spectral density (Kondo peak) splits and the density of the doublet of higher energy Ï2Ï(Ï) shifts above the Ferrmi energy. The Kondo temperature TK (determined by the half-width at half maximum of the Kondo peak in density of the doublet of lower energy Ï1Ï(Ï)) decreases dramatically. The variation of TK with δ is reproduced by a simple variational calculation.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
L. Tosi, P. Roura-Bas, A.A. Aligia,