Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in spontaneous parametric down conversion

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function

Nondestructive measurement of intensity of optical fields using spontaneous parametric down conversion

Results of nondestructive measurements of intensity (photons per mode) of light from different sources are discussed. The procedure of measurement does not destroy the state of the optical field. The method is based on using the second order nonlinearity of crystal media lacking a center of symmetry and the nonclassical properties of the process of Spontaneous Parametric Down Conversion (SPDC)

High-visibility multi-photon interference of Hanbury Brown - Twiss type for classical light

Difference-phase (or Hanbury Brown - Twiss type) intensity interference of classical light is considered in higher orders in the intensity. It is shown that, while the visibility of sum-phase (NOON-type) interference for classical sources drops with the order of interference, the visibility of difference-phase interference has opposite behavior. For three-photon and four-photon interference of two coherent sources, the visibility can be as high as 81.8% and 94.4%, respectively. High-visibility three-photon and four-photon interference of space-time and polarization types has been observed in experiment, for both coherent and pseudo-thermal light.Comment: 11 pages, 9 figure

Heavy-quarkonium creation and annihilation with O(alpha_s^3 ln(alpha_s)) accuracy

We calculate the O(alpha_s^3 ln(alpha_s)) contributions to the heavy-quarkonium production and annihilation rates. Our result sheds new light on the structure of the high-order perturbative corrections and opens a new perspective for a high-precision theoretical analysis. We also determine the three-loop anomalous dimensions of the nonrelativistic vector and pseudoscalar currents.Comment: 10 pages (Latex). Eq. (6) corrected, conclusions unchange

Plasma-Like Negative Capacitance in Nano-Colloids

A negative capacitance has been observed in a nano-colloid between 0.1 and 10^-5 Hz. The response is linear over a broad range of conditions. The low-omega dispersions of both the resistance and capacitance are consistent with the free-carrier plasma model, while the transient behavior demonstrates an unusual energy storage mechanism. A collective excitation, therefore, is suggested.Comment: 3 pages, 3 figure

Optimization of thin film growth: Materials for energy storage and conversion

Through three examples taken in the field of energy storage and conversion, this paper reports how the property of thin films can be optimized by tuning the growth conditions. Focusing on the influence of the film composition, the substrate temperature and the pressure, oxides, fluorides, metal and hydrides thin films were successfully grown using the Pulsed Laser Deposition technique. A careful screening among a large range of metal addition (M=Co, Ta, W<20 %) enables the determination of the Ta and W compositions leading to the highest cycling stability of electrochromic Ni-based oxide thin films cycled in KOH electrolyte. The optical properties of Mg thin films are strongly sensitive to the chamber pressure as shiny metallic and transparent films are deposited in vacuum and under an Ar/H2 mixture, respectively. Optical changes were also achieved by ex situ hydrogenation of Mg-Cx films. Finally, the benefit of enlarging substrate temperatures to negative values is illustrated through the example of FeFx thin films, for which the substrate temperature is a key factor governing the FeF2 or/and FeF3 phase deposition.Through three examples taken in the field of energy storage and conversion, this paper reports how the property of thin films can be optimized by tuning the growth conditions. Focusing on the influence of the film composition, the substrate temperature and the pressure, oxides, fluorides, metal and hydrides thin films were successfully grown using the Pulsed Laser Deposition technique. A careful screening among a large range of metal addition (M=Co, Ta, W<20 %) enables the determination of the Ta and W compositions leading to the highest cycling stability of electrochromic Ni-based oxide thin films cycled in KOH electrolyte. The optical properties of Mg thin films are strongly sensitive to the chamber pressure as shiny metallic and transparent films are deposited in vacuum and under an Ar/H2 mixture, respectively. Optical changes were also achieved by ex situ hydrogenation of Mg-Cx films. Finally, the benefit of enlarging substrate temperatures to negative values is illustrated through the example of FeFx thin films, for which the substrate temperature is a key factor governing the FeF2 or/and FeF3 phase deposition

Two-Loop Sudakov Form Factor in a Theory with Mass Gap

The two-loop Sudakov form factor is computed in a U(1) model with a massive gauge boson and a $U(1)\times U(1)$ model with mass gap. We analyze the result in the context of hard and infrared evolution equations and establish a matching procedure which relates the theories with and without mass gap setting the stage for the complete calculation of the dominant two-loop corrections to electroweak processes at high energy.Comment: Latex, 5 pages, 2 figures. Bernd Feucht is Bernd Jantzen in later publications. (The contents of the paper is unchanged.