Recent measurements of the surface impedance in YBa2Cu307~single crystals show large in-plane anisotropy which implies that orthorhombicity due to the Cu-0 chains is not small. In addition, the controversy between the d-wave and the s-wave order parameter persists. In the framework of the orthorhombic symmetry, an order parameter with (d+ s)-wave symmetry is considered in an attempt to understand current experimental results. We provide a detailed study of the characteristics of such an order parameter in the low-temperature behavior of the penetration depth, the density of states, and the T, suppression in the presence of nonmagnetic impurity scattering. The results are discussed in comparison with the d-wave and the anisotropic s-wave cases.

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We investigated scaling behaviors for NiO nanowire array devices with different nanowire diameters. Plots of the reset current and the third harmonic generation signal as a function of the on-state resistance (R0) show scaling behaviors for all devices, such as NiO film devices. However, the scaling exponents of NiO nanowire devices were different from those of NiO film devices, and hence the fractal dimension estimated from the scaling exponent was smaller for the NiO nanowire devices than for the NiO film devices. This decrease in the fractal dimension was attributed to the confinement of the conducting filaments within each nanowire.

We study the spin miniband structure and the ballistic spin‐polarized transport of a magnetic superlattice (MSL), formed by inhomogeneous magnetic field in a semiconductor nanowire. Based on the transfer matrix theory and Bloch's theorem, we calculate the energy dispersion having spin‐minibands and spin‐minigaps due to Bloch periodicity and spin‐dependent ballistic conductance for various geometrical and physical parameters. Results show that full spin‐polarization in the ballistic conductance of the system occurs clearly for each spin, and that the fully spin‐polarized range for each spin can be enhanced by modulation of geometrical and physical parameters. Schematic diagram of a MSL constructed by superconducting gridded mask on the top of a quantum wire formed by the split gate technique in two‐dimensional electron gas system. Transverse modes in Q1DEG serve as transmission channels.

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