Electron-ion interaction in a nearly ferroelectric metal

Abstract

We calculate the electron-ion potential for a thin metallic layer ͑in the a-b plane͒ sandwiched between two semi-infinite dielectrics. The dielectric constant of the dielectrics varies strongly in the a-b plane. We show that there is an overscreening effect, and the electron-ion interaction is strongly enhanced, for certain values of the parameters. This suggests the possibility of a greatly enhanced electron-phonon coupling in a nearly ferroelectric metal, such as the high-T c perovskites.

Magnetism and Antiferroelectricity inMgB6

“…The situation here is however more complex as, although there is density of states at the Fermi level, this is associated to partially localized states. Their screening can be inefficient to a point that local electric dipoles still form [29,30]. Our results indeed confirm such a hypothesis as the Mg ions remain in their off-center positions as B vacancies are introduced in the cell.…”

Fluorescence Near Gold Nanoparticles for DNA Sensing

“…32,33 Therefore, we have taken advantage of the analytical model developed by Gersten and Nitzan. 20 The wavelength of the dipole was set at 574 nm, corresponding to the emission wavelength of the Atto dye. The decay rate of the excited molecule in absence of the optical antenna can be denoted as…”

“…To better understand the physical principles behind, theoretical modeling of these quenching and enhancement efficiencies have been carried out extensively during the past decades using model systems. [20][21][22][23] Still, in view of the limited number of biological results, questions remain on metal particles coated with biomolecules. So far, mainly because the number of molecules responsible for fluorescence emission was not studied in depth, the reported results were mainly semiquantitative.…”