Publications by authors named "P Calvani"

Microbial biofilm is of paramount importance in the development of mucositis or peri-implantitis in patients with dental implants. This study was designed to investigate whether an electromagnetic field at high frequency waves directly applied on 33 titanium implants could remove experimentally-induced Enterococcus faecalis bacterial biofilm. A specially designed device (X-IMPLANT) was used to generate the electromagnetic field, with output power of 8 W, supply frequency (action/pause) 3/2s, and an output frequency of 625±5% kHz in plastic devices containing the biofilm-covered implants immersed in sterile saline.

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The growing need for new and reliable surface sensing methods is arousing interest in the electromagnetic excitations of ultrathin films, i.e., to generate electromagnetic field distributions that resonantly interact with the most significant quasi-particles of condensed matter.

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A new optical setup is described that allows the reflectivity at grazing incidence to be measured, including ultrathin films and two-dimensional electron systems (2DES) down to liquid-helium temperatures, by exploiting the Berreman effect and the high brilliance of infrared synchrotron radiation. This apparatus is well adapted to detect the absorption of a 2DES of nanometric thickness, namely that which forms spontaneously at the interface between a thin film of LaAlO and its SrTiO substrate, and to determine its Drude parameters.

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The Berreman effect (BE) allows one to study the electrodynamics of ultrathin conducting films at the surface of dielectrics by use of grazing-angle infrared spectroscopy and polarized radiation. Here, we first apply the BE to the two-dimensional electron system (2DES) at the interface between a high-purity film of the topological insulator Bi_{2}Se_{3} and its sapphire substrate. We determine for the 2DES a charge density n_{s}=(8±1)×10^{12}  cm^{-2}, a thickness d=0.

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SrRuO (SRO) is a perovskite increasingly used in oxide-based electronics both for its intrinsic metallicity, which remains unaltered in thin films and for the ease of deposition on dielectric perovskites like SrTiO, (STO) to implement SRO/STO microcapacitors and other devices. In order to test the reliability of SRO/STO also as high-current on-chip conductor, when the SRO dimensions are pushed to the nanoscale, here we have measured the electrodynamic properties of arrays of nanoribbons, fabricated by lithography starting from an ultrathin film of SRO deposited on a STO substrate. The nanoribbons are 6 or 4 nm thick, 400, 200 and 100 nm wide and 5 mm long.

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