Spectral Density of the Two-Impurity Anderson Model
نویسندگان
چکیده
We investigate static and dynamical ground-state properties of the twoimpurity Anderson model at half filling in the limit of vanishing impurity separation using the dynamical density-matrix renormalization group method. In the weakcoupling regime, we find a quantum phase transition as function of inter-impurity hopping driven by the charge degrees of freedom. For large values of the local Coulomb repulsion, the transition is driven instead by a competition between local and non-local magnetic correlations. We find evidence that, in contrast to the usual phenomenological picture, it seems to be the bare effective exchange interactions which trigger the observed transition. PACS numbers: 71.27.+a, 71.55.Ak, 75.30.Hx, 75.20.Hr Spectral Density of the Two-Impurity Anderson Model 2
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