Thermal counting statistics in an atomic two-mode squeezed vacuum state

We measure the population distribution in one of the atomic twin beams generated by four-wave mixing in an optical lattice. Although the produced two-mode squeezed vacuum state is pure, each individual mode is described as a statistical mixture. We confirm the prediction that the particle number follows an exponential distribution when only one spatio-temporal mode is selected. We also show that this distribution accounts well for the contrast of an atomic Hong--Ou--Mandel experiment. These experiments constitute an important validation of our twin beam source in view of a future test of a Bell inequalities.Comment: SciPost submissio

High quality SiO 2 /diamond interface in O-terminated p-type diamond MOS capacitors

International audienceMetal oxide semiconductor (MOS) capacitors were fabricated based on oxygen-terminated p-type (100) oriented diamond and SiO 2 grown by atomic layer deposition. A detailed electrical characterization consisting of I–V, C–V, and C–F was performed in order to analyze the electrical properties of the structure. The MOS capacitor presented no detectable leakage current in forward and very low leakage current in reverse sustaining at least 6 MV/cm without degradation. The C–V measurements showed depletion and deep depletion regimes in forward and accumulation regimes in reverse, with a low density of interface states of [Formula: see text] along the diamond bandgap. The latter results were further validated by conductance and capacitance vs frequency measurements

Novel heteroleptic precursors for atomic layer deposition of TiO2

Two novel heteroleptic titanium precursors for the atomic layer deposition (ALD) of TiO2 were investigated, namely, titanium (N,N'-diisopropylacetamidinate)tris(isopropoxide) (Ti(OiPr)3(NiPr-Me-amd)) and titanium bis(dimethylamide)bis(isopropoxide) (Ti(NMe2)2(OiPr)2). Water was used as the oxygen source. These two precursors are liquid at room temperature and present good volatility, thermal stability and reactivity. The self-limiting ALD-growth mode was confirmed at 325 °C for both precursors. The titanium (N,N'-diisopropylacetamidinate)tri(isopropoxide)/water process showed an ALD window at 300–350 °C, and titanium bis(dimethylamide)bis(isopropoxide) exhibited an interestingly high growth rate of 0.75 Å/cycle at 325 °C. The films were crystallized to the anatase phase in the as-deposited state. X-ray photoelectron spectroscopy analysis demonstrated that the films were pure and close to the stoichiometric composition. The refractive indexes and absorption coefficient of the films were measured by spectroscopic ellipsometry

Novel heteroleptic precursors for atomic layer deposition of TiO2

Two novel heteroleptic titanium precursors for the atomic layer deposition (ALD) of TiO2 were investigated, namely, titanium (N,N'-diisopropylacetamidinate)tris(isopropoxide) (Ti(OiPr)3(NiPr-Me-amd)) and titanium bis(dimethylamide)bis(isopropoxide) (Ti(NMe2)2(OiPr)2). Water was used as the oxygen source. These two precursors are liquid at room temperature and present good volatility, thermal stability and reactivity. The self-limiting ALD-growth mode was confirmed at 325 °C for both precursors. The titanium (N,N'-diisopropylacetamidinate)tri(isopropoxide)/water process showed an ALD window at 300–350 °C, and titanium bis(dimethylamide)bis(isopropoxide) exhibited an interestingly high growth rate of 0.75 Å/cycle at 325 °C. The films were crystallized to the anatase phase in the as-deposited state. X-ray photoelectron spectroscopy analysis demonstrated that the films were pure and close to the stoichiometric composition. The refractive indexes and absorption coefficient of the films were measured by spectroscopic ellipsometry

Atomic layer deposition and characterization of vanadium oxide thin films

In this study, VOx films were grown by atomic layer deposition (ALD) using V(NEtMe)4 as the vanadium precursor and either ozone or water as the oxygen source. V(NEtMe)4 is liquid at room temperature and shows good evaporation properties. The growth was investigated at deposition temperatures from as low as 75 °C, up to 250 °C. When using water as the oxygen source, a region of constant growth rate (ca. 0.8 Å/cycle) was observed between 125 and 200 °C, with the ozone process the growth rate was significantly lower (0.31–0.34 Å/cycle). The effect of the process conditions and post-deposition annealing on the film structure was investigated. By varying the atmosphere under which the films were annealed, it was possible to preferably form either VO2 or V2O5. Atomic force microscopy revealed that the films were smooth (rms <0.5 nm) and uniform. The composition and stoichiometry of the films were determined by X-ray photoelectron spectroscopy. Conformal deposition was achieved in demanding high aspect ratio structure

Atomic layer deposition and characterization of vanadium oxide thin films

In this study, VOx films were grown by atomic layer deposition (ALD) using V(NEtMe)4 as the vanadium precursor and either ozone or water as the oxygen source. V(NEtMe)4 is liquid at room temperature and shows good evaporation properties. The growth was investigated at deposition temperatures from as low as 75 °C, up to 250 °C. When using water as the oxygen source, a region of constant growth rate (ca. 0.8 Å/cycle) was observed between 125 and 200 °C, with the ozone process the growth rate was significantly lower (0.31–0.34 Å/cycle). The effect of the process conditions and post-deposition annealing on the film structure was investigated. By varying the atmosphere under which the films were annealed, it was possible to preferably form either VO2 or V2O5. Atomic force microscopy revealed that the films were smooth (rms <0.5 nm) and uniform. The composition and stoichiometry of the films were determined by X-ray photoelectron spectroscopy. Conformal deposition was achieved in demanding high aspect ratio structure