Interlayer hopping properties of electrons in layered metals

A formalism is proposed to study the electron tunneling between extended states, based on the spin-boson Hamiltonian previously used in two-level systems. It is applied to analyze the out--of--plane tunneling in layered metals considering different models. By studying the effects of in--plane interactions on the interlayer tunneling of electrons near the Fermi level, we establish the relation between departure from Fermi liquid behavior driven by electron correlations inside the layer and the out of plane coherence. Response functions, directly comparable with experimental data are obtained

Medical Practice under Managed Care: Cost-control Mechanisms and Impact on Quality of Service

The paper investigates the US experience of Managed Care. It describes the cost controlling measures and the new modes of payment that were implemented along with managed Care. Using theory and field surveys, it reviews how these measures have affected physician practices. The paper also investigates their impact on the quality of health services. Copyright Springer Science + Business Media, Inc. 2005HMO, Managed Care, patient, US, physician payment,