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Shigeki Matsuo

Publications and source records attributed to Shigeki Matsuo.

4 recordsLinked to original sources

Possibility of Gravitational Tempering in Colloidal Epitaxy to Obtain a Perfect Crystal

We have performed Monte Carlo simulations of hard spheres on a pattern under gravity. We have found that a crystal formed at a moderate gravity strength contains essentially no defects while one formed at a higher strength gravity contains a significant amount of defects. This result suggests the possibility of using gravitational-tempering in a colloidal epitaxy to reduce the number of defects in colloidal crystals. Moreover, we wish to emphasize the possibility to obtain a perfect crystal.

cond-mat.soft

Monte Carlo simulation of defects in hard-sphere crystal grown on a square pattern

Monte Carlo simulations of hard-sphere (HS) crystal grown on a square patterned wall under gravity have been performed. While previous simulations were performed with step-wise controlled gravity, in the present simulations constant gravity has been applied from the first. In the case in which a flat wall is used as the bottom wall, if a large gravity is suddenly applied, the system does polycrystallize. On the other hand, in the present simulations, despite the sudden application of gravity, the system has not polycrystallize. Crystalline nucleation on the square pattern and successive crystal growth upward are suggested to overcome the homogeneous nucleation inside and result in. Defect disappearance, which has been essentially the same as that for the case with step-wise controlled gravity, has also observed for the present case. The characteristic of the square patterned bottom wall simulation with a large horizontal system size has been existence of triangular defects suggesting stacking tetrahedra.

cond-mat.soft

Microfabrication of Three-Dimensional Structures in Polymer and Glass by Femtosecond Pulses

We report three-dimensional laser microfabrication, which enables microstructuring of materials on the scale of 0.2-1 micrometers. The two different types of microfabrication demonstrated and discussed in this work are based on holographic recording, and light-induced damage in transparent dielectric materials. Both techniques use nonlinear optical excitation of materials by ultrashort laser pulses (duration < 1 ps).

physics.optics

Comment: Anomalous Anisotropic Light Scattering in Ge-Doped Silica Glass

This is a comment on a paper by Kazansky et al. appeared in Phys. Rev. Lett., 82, 2199 (1999). We demonstrate that the bremsstrahlung of photoelectrons, which oscillate in the light field of an ultrashort laser pulse, accounts for the anomalous anisotropic light scattering, the "propeller effect", described in the paper of Kazansky et al. This mechanism of light emission could explain some results of white-light continuum generation and dielectric breakdown emission.

physics.plasm-ph