A model for the formation of helical multishell gold nanowires is proposed and is confirmed with quantum mechanical molecular dynamics simulations. The model can explain the magic number of the helical gold nanowires ...
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A model for the formation of helical multishell gold nanowires is proposed and is confirmed with quantum mechanical molecular dynamics simulations. The model can explain the magic number of the helical gold nanowires in the multishell structure. The reconstruction from ideal nonhelical to realistic helical nanowires consists of two stages: dissociations of atoms on the outermost shell from atoms on the inner shell and slip deformations of atom rows generating (111)-like structure on the outermost shell. The elementary processes are governed by competition between energy loss and gain by s and d electrons together with the width of the d band. The possibility for the helical nanowires of platinum, silver, and copper is discussed.
A spatial light phase modulator with a high transmission> 85% (260-1100 nm) and a phase modulation capability of 53 radian at 260 nm and 12 radian at 1100 nm has been developed for the first time.
ISBN:
(纸本)9781424435906
A spatial light phase modulator with a high transmission> 85% (260-1100 nm) and a phase modulation capability of 53 radian at 260 nm and 12 radian at 1100 nm has been developed for the first time.
The purpose of this study is to generate sub-femtosecond class optical pulses using multiple coherent anti-Stokes Raman scattering (CARS) signals in solids at room temperature.
The purpose of this study is to generate sub-femtosecond class optical pulses using multiple coherent anti-Stokes Raman scattering (CARS) signals in solids at room temperature.
We developed an angularly dispersed noncollinear optical parametric amplifier with a 300-THz bandwidth (550-1000 nm) for the first time. To the best of our knowledge, this is the broadest parametric gain.
ISBN:
(纸本)9781424435906
We developed an angularly dispersed noncollinear optical parametric amplifier with a 300-THz bandwidth (550-1000 nm) for the first time. To the best of our knowledge, this is the broadest parametric gain.
We have prepared polycrystalline samples of the Ruddlesden-Popper La 2-2x Ca 1+2x Mn 2 O 7 phase and determined their crystal structure and thermoelectric properties above room temperature. Single-phase samples with ...
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We have prepared polycrystalline samples of the Ruddlesden-Popper La 2-2x Ca 1+2x Mn 2 O 7 phase and determined their crystal structure and thermoelectric properties above room temperature. Single-phase samples with tetragonal I4/mmm space group are obtained for the samples with 0.50 les x les 1.00; the corresponding valence state of Mn is from 3.5 to 4.0. With increasing x, the a-axis length gradually decreases from 3.8268(4) Aring (x = 0.5) to 3.7078(2) Aring (x = 1.0), while the c-axis length increases from 19.197(3) Aring(x = 0.5) to 19.438(1) Aring(x = 1.0). As expected, all the samples exhibit negative Seebeck coefficients, S. The absolute value of S increases with increasing x, and the phases become electrically conductive at high temperatures. For example, the sample with x = 0.50 exhibits the electrical conductivity, sigma = 35 S/cm and S = -40muV/K at 1123 K, compared with those of the sample with x = 0.95 of sigma = 18 S/cm and S = -175 muV/K. The highest ZT ~0.03 with the power factor of 5.5 x 10 -5 W/mK 2 , has been obtained for the x = 0.95 sample at 1123 K.
Free-space quantum key distribution (QKD) is expected to realized a global system for QKD based on a network of ground to satellite or satellite to satellite, and thus to extend the distance limit and the utility of Q...
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Free-space quantum key distribution (QKD) is expected to realized a global system for QKD based on a network of ground to satellite or satellite to satellite, and thus to extend the distance limit and the utility of QKD method (Schmitt-Manderbach et al., 2007). We report an experimental demonstration of free-space continuous-variable QKD (CV-QKD). We use a 1.55 m-wavelength pulsed diode laser and a pulsed homodyne detector. We have demonstrated free-space CV-QKD using a novel collinear interferometer. Our result shows the feasibility of practical free-space CV-QKD. We believe it will be an important step for the future study of free-space CV-QKD.
Electronic structure of stripe ordered La2−xSrxNiO4 is investigated. The system with x=13 is insulator, in LSDA+U calculations, and shows charge and spin stripe, consistent with the experimental results. A highly corr...
Electronic structure of stripe ordered La2−xSrxNiO4 is investigated. The system with x=13 is insulator, in LSDA+U calculations, and shows charge and spin stripe, consistent with the experimental results. A highly correlated system of x=12 is studied by using exact diagonalization of the multiorbital many-body Hamiltonian derived from LDA calculations and including on-site and intersite Coulomb interactions. The fluctuation of the residual spin on Ni3+ (hole) site couples with the charge fluctuation between Ni3+ and Ni2+ states and this correlation lowers the total energy. The resultant ground state is an insulator with charge and spin stripe of the energy gap 0.9eV, consistent with the observed one. The on-site Coulomb interaction stabilizes integral valency of each Ni ion (Ni3+ and Ni2+), but does not induce the charge order. Two quantities, intersite Coulomb interaction and anisotropy of hopping integrals, play an important role to form the charge and spin stripe order in a system of x=12.
We have demonstrated purification of a single qubit by two collinear photons, one of which was time-delayed. Our method can be applied to a single qubit many times, and the qubit can be purified to an arbitrarily high...
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We have demonstrated purification of a single qubit by two collinear photons, one of which was time-delayed. Our method can be applied to a single qubit many times, and the qubit can be purified to an arbitrarily high degree of purity. Thus, by repeating this method we can make the statistical error that single qubits incur along a transmission channel much smaller.
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