Historical and interpretative aspects of quantum mechanics: a physicists' naive approach

Many theoretical predictions derived from quantum mechanics have been confirmed experimentally during the last 80 years. However, interpretative aspects have long been subject to debate. Among them, the question of the existence of hidden variables is still open. We review these questions, paying special attention to historical aspects, and argue that one may definitively exclude local realism on the basis of present experimental outcomes. Other interpretations of Quantum Mechanics are nevertheless not excluded.Comment: 30 page

A simple method for the determination of strains in epitaxial films: application to Eu(110) deposited on a Nb(110) buffer

In order to determine the strain tensor in a 375 nm thick Eu(110) epitaxial thin film, we have developed a new method, based on the accurate determination of the lattice vectors by high resolution X-ray diffraction. We show that a biaxial strain model gives a good representation of the state of the strains field in the film. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005

Surface and interface cerium electronic configuration in Ce/Fe (100)

The cerium electronic configuration of very thin films deposited on Fe(100) has been studied by core level photoemission. In the low-coverage regime ($\le 1$ monolayer), cerium atoms are in a trivalent state ($4f^1$ configuration). For larger coverages, cerium atoms exhibit a mixed valent state. This behaviour reflects the valence change of covered cerium atoms at the interface and results from the increase in the hybridization strength for these interface atoms. Owing to an original method, we were able to directly decompose our experimental spectra in two contributions corresponding to the covered (“bulk”) and non-covered (surface) atoms

DEPENDENCE OF THE ELECTRONIC STRUCTURE OF YBa2Cu3O7-∂ CERAMICS ON OXYGEN STOICHIOMETRY : A PHOTOEMISSION AND PHOTOABSORPTION STUDY

X-ray photoemission (XPS) and X-ray absorption (XAS) have been performed on YBa2Cu3O7-∂ ceramics as a function of ∂ (0.1 < ∂ < 0.7). The results show the modifications of the Cu electronic structure around the superconducting-semiconducting transition. XPS and XAS experiments give complementary informations allowing the identification of Cu+, Cu2+ and the so-called Cu3+ configurations as a function of ∂

Electronic structure of YBa2Cu3O7-δ as a function of δ : determination of the valency of copper atoms by X-ray absorption and photoemission experiments

The electronic structure of YBa2Cu3O7- δ compounds has been studied in the range 0 < 8 < 1, by performing X-ray Absorption (XAS) on the Cu K edge and X-ray Photoemission experiments (XPS) on the Cu2p and O1s core levels. The absorption experiments have been performed by following continuously the Copper K edge during isothermal cycles of oxy-deoxygenation. Such experiments bring the absolute modifications of the electronic structure, thus minimizing the use of reference compounds in the discussion. An highly correlated mixed-valent ground state in these high Tc materials is suggested. A comparison with the XPS results is made and it confirms this assumption