Wednesday, November 28, 2012

1211.6333 (D. Rotter et al.)

Double Exchange model for nanoscopic clusters    [PDF]

D. Rotter, A. Valli, G. Sangiovanni, K. Held
We solve the double exchange model on nanoscopic clusters exactly, and specifically consider a six-site benzene-like nanocluster. This simple model is an ideal testbed for studying magnetism in nanoclusters and for validating approximations such as the dynamical mean field theory (DMFT). Non-local correlations arise between neighboring localized spins due to the Hund's rule coupling, favoring a short-range magnetic order of ferro- or antiferromagnetic type. For a geometry with more neighboring sites or a sufficiently strong hybridization between leads and the nanocluster, these non-local correlations are less relevant, and DMFT can be applied reliably.
View original: http://arxiv.org/abs/1211.6333

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