Transition between SU(4) and SU(2) Kondo effect

摘要: Abstract Motivated by experiments in nanoscopic systems, we study a generalized Anderson, which consist of two spin degenerate doublets hybridized to singlet the promotion an electron conduction bands, as function energy separation δ between both doublets. For = 0 or very large, model is equivalent one-level SU( N ) Anderson model, with 4 and 2 respectively. We evolution spectral density for ( ρ 1 σ ω their width Kondo limit varied, using non-crossing approximation (NCA). As increases, peak at Fermi (Kondo peak) splits doublet higher shifts above Ferrmi energy. The temperature TK (determined half-width half maximum lower decreases dramatically. variation reproduced simple variational calculation.