Incoherence in bilayer systems with strong electronic correlations

We present results for the one-particle properties and c-axis transport for exchange-coupled bilayer systems with strong electronic correlations in th e paramagnetic phase. The model is solved within the dynamical mean-field t heory (DMFT). By considering an effective two-site impurity we are able to treat the coupling between the layers in the diagonalization of the effecti ve impurity exactly. The one-particle properties and the optical conductivi ty between the planes are studied, giving insight into a possible suppressi on of the one-particle hopping between the planes by the antiferromagnetic coupling. A strong renormalization of the bilayer splitting up to a complet e suppression by the antiferromagnetic coupling is found. In the optical co nductivity a strong blocking of the charge dynamics between the planes can be seen, accompanied by a low-energy excitation which must be attributed to inter-plane spin fluctuations.