High-fidelity teleportation beyond the no-cloning limit and entanglement swapping for continuous variables

We experimentally demonstrate continuous-variable quantum teleportation beyond the no-cloning limit. We teleport a coherent state and achieve the fidelity of 0.70 +/- 0.02 that surpasses the no-cloning limit of 2/3. Surpassing the limit is necessary to transfer the nonclassicality of an input quantum state. By using our high-fidelity teleporter, we demonstrate entanglement swapping, namely, teleportation of quantum entanglement, as an example of transfer of nonclassicality.     

Endoscopic Observation of Tissue by Narrowband Illumination

We propose a new illumination method for a medical endoscope: narrow band imaging (NBI), in which the spectral bandwidth of the filtered light is narrowed. To confirm how the spectral specifications of the filtered light influence a reproduced image, an experiment was conducted observing the endoscopic images of the back mucosa of a human tongue. In addition, the effect of NBI on endoscopic images was investigated through preliminary clinical tests in colonoscopy and upper gastrointestinal endoscopy. It has been shown that NBI can enhance the capillary pattern and the crypt pattern on the mucosa. These patterns are useful features for diagnosing an early cancer.     

Multi-Terabit Long-Haul Transmission System Utilizing Distributed Raman Amplification Technologies

Here we summarize multi-terabit long-haul transmission experiment and distributed Raman amplification (DRA) technologies. As well, we investigate the configuration of dispersion-managed fibers for the DRA-based system from the viewpoint of the fiber non-linear effect and required pumping power.     

Homogeneous ZnO Nanoparticles by Flame Spray Pyrolysis

Zinc oxide (ZnO) nanoparticles were made by flame spray pyrolysis (FSP) of zinc acrylate–methanol–acetic acid solution. The effect of solution feed rate on particle specific surface area (SSA) and crystalline size was examined. The average primary particle diameter can be controlled from 10 to 20nm by the solution feed rate. All powders were crystalline zincite. The primary particle diameter observed by transmission electron microscopy (TEM) was in agreement with the equivalent average primary particle diameter calculated from the SSA as well as with the crystalline size calculated from the X-ray diffraction (XRD) patterns for all powders, indicating that the primary particles were rather uniform in diameter and single crystals. Increasing the solution feed rate increases the flame height, and therefore coalescence and/or surface growth was enhanced, resulting in larger primary particles. Compared with ZnO nanoparticles made by other processes, the FSP-made powder exhibits some of the smallest and most homogeneous primary particles. Furthermore, the FSP-made powder has comparable BET equivalent primary particle diameter with but higher crystallinity than sol–gel derived ZnO powders.     

Dynamical structure of peptide molecules: Fourier transform microwave spectroscopy and ab initio calculations of N-methylformamide

Rotational spectra of both trans and cis forms of the N-methylformamide normal as well as deuterated (HCONDCH₃, referred to as N-D) species were observed by Fourier transform microwave spectroscopy in the frequency region from 5 to 118 GHz. Samples were prepared in the form of a beam by a pulsed jet valve maintained at 50 °C and were introduced in a high-vacuum cavity cell, with either Ne or Ar as a carrier gas at a backing pressure of 100 kPa. The observed spectra were analyzed to yield molecular parameters including rotational constants and barrier, V₃, to CH₃ internal-rotation: 53.9 (6) and 301 (4) cm⁻¹ for the trans and cis forms of the normal species, respectively, and 41.9 (6) and 309 (4) cm⁻¹ for the trans and cis forms of the N-D species, respectively. Spectra of four trans isotopologues with ¹³C, ¹⁵N, or ¹⁸O singly-substituted in the internal-rotation A state were observed and analyzed to derive the r_s structure of the trans form. For comparison with the experimental data, ab initio calculations were carried out at MP2/6-31G∗∗ level to derive molecular structure, potential barrier to CH₃ internal rotation, and the energy difference between the cis and trans forms. An extensive coupling was found between the CH₃ internal rotation and N-H out-of-plane bending, suggesting that the potential function for the CH₃ internal-rotation deviates considerably from a simple cos(3α) form. The effects of the V₆ term is briefly discussed.     

单晶生长炉全局热分析(3)-自由界面形状的影响

本文在平坦自由表面非定常三维全局热分析模型的基础上,考虑自由表面形状的弯曲性,通过大量数值模拟,研究了弯曲自由表面对熔液流动、炉内全局温度场分布等的影响.研究表明:弯曲自由表面更易引起熔液流动振荡,且降低晶体生长界面反转的临界Re数,使结果更接近实际,从而使单晶生长全局热分析模型比前文更完善.     

Emulsion Combustion and Flame Spray Synthesis of Zinc Oxide/Silica Particles

Two flame spray methods, emulsion combustion method (ECM) and flame spray pyrolysis (FSP), were compared for synthesis of pure and mixed SiO₂ and ZnO nanoparticles. The effect of silicon precursor was investigated using liquid hexamethyldisiloxane (HMDSO) or SiO₂ sol, while for ZnO zinc acetate (ZA) was used. Gas phase reaction took place when using HMDSO as Si precursor, forming nanoparticles, whereas the SiO₂ sol used as Si source was not evaporated in the flame, creating large aggregates of the sol particles (e.g. 1 m). The FSP of ZA produced ZnO homogeneous nanoparticles. Lower flame temperatures in ECM than in FSP resulted in mixed gas and liquid phase reaction, forming ZnO particles with inhomogeneous sizes. The FSP of HMDSO and ZA led to intimate gas-phase mixing of Zn and Si, suppressing each other's particle growth, forming nanoparticles of 19 nm in BET-equivalent average primary particle diameter. Nucleation of ZnO and SiO₂ occurred independently by ECM of HMDSO and ZA as well as by FSP of the SiO₂ sol and ZA, creating a ZnO and SiO₂ mixture. The reaction of ZnO with SiO₂ was likely to be enhanced by ECM of the SiO₂ sol and ZA where both Zn and Si species were not evaporated completely, resulting in ZnO, -willemite and Zn_1.7SiO₄ mixed phase.     

Direct micropatterning of high dielectric BaTiO3 films by laser-induced pyrolysis with a nano-crystalline seeding technique

A direct patterning method of dielectric BaTiO₃ (BT) films is proposed, which applies laser-induced pyrolysis in combination with nano-crystalline seeding technique. A precursor solution of a BT complex alkoxide containing BT nano-crystalline particles with polyvinylpyrollidone (PVP) as dispersion stabilizer was spin-coated on Pt substrate. An Ar⁺ laser beam was focused and scanned on spin-coated BT films, which induced pyrolysis and crystallization of the films with spatial selectivity. Micropatterns were obtained by striping laser-unirradiated regions on the films with HCl aqueous solution. Raman spectra of the micropattern confirmed that the structures were tetragonal crystalline BT. Clear micropatterns with a line width of ca. 3 μm and an interval of 5 μm were formed at PVP concentrations of 25 and 50 kg/m³. The dielectric constant and dissipation factor of the film fabricated at a laser energy density of 27 MW/cm² and a scanning speed of 25 μm/s attained 76.2 and 0.07, respectively, for a measurement frequency of 100 kHz.     

Study of Strangeness Photoproduction on the Neutron in the Threshold Region

Photoproduction of the neutral kaon on the deuteron has been investigated at the Research Center for Electron Photon Science, Tohoku University. We constructed the Neutral Kaon Spectrometer-2 for the detection of charged particles from the decay of the neutral kaon and the hyperon. We obtained a momentum distribution of K ⁰ with the inclusive measurement. It was consistent with the previous measurement. The total cross section of γ + d → K ⁰ + Λ + p was estimated from the measured integral cross section of γ + d → Λ + X. The total cross section with respect to the photon energy was compared with the theoretical calculations. It favored the Saclay-Lyon A model calculation with the ratio of the neutral to charged coupling constants of the axial-vector meson, K ₁, as ~ ?1.5. The energy dependence and the magnitude of the total cross section were similar to the total cross section of γ + p → K ⁺ Λ.     

Effect of phosphorus and copper additions on the structure of Pt and Pt–Cu nanoparticles in a radiation-induced reduction method

A facile chemical process has been developed for the preparation of magnetic FeCo nanoparticles. The FeCo nanoparticles were mono-dispersed, obtained by the safe and ecofriendly method, possessed saturation magnetization up to 187 emu/g, and demonstrated excellent chemical stability. In this work, we have studied how to control Fe/Co ratio by variation of precursor ratio, and how to vary particle size from 9.3 to 12.3 nm by surfactant amount used. The cytotoxicity of as-synthesized nanoparticles was investigated after coating with the poly(methyl methacrylate-co-butyl acrylate) by the emulsion process and the results demonstrated high biocompatibility. Similarly, the same synthesis method was used with the single precursor FeO(OH) or Co₃O₄. The results showed that this method can also fabricate 10 nm mono-dispersed spherical Fe₃O₄ particles and self-assembly Co nanoneedles.