We develop a tight-binding model description of semi-Dirac electronic spectra, with highly anisotropic dispersion around point Fermi surfaces, recently discovered in electronic structure calculations of VO2-TiO2 nanoheterostructures. We contrast their spectral properties with the well-known Dirac points on the honeycomb lattice relevant to graphene layers and the spectra of bands touching each ...

We consider a thin-film normal-metal/superconductor junction in the presence of an externally applied in-plane magnetic field for several symmetries of the superconducting order parameter. For p-wave superconductors, a strongly spin-polarized current emerges due to an interplay between the nodal structure of the superconducting order parameter, the existence or nonexistence of zero-energy surfa...

We utilized a local density functional potential, the linear combination of atomic orbital (LCAO) method, and the BZW procedure to study the electronic structure of 3Cand 4H-SiC. We present the calculated energy bands, band-gaps, effective masses of n-type carriers, and critical point transition energies. There is good agreement between the calculated electronic properties and experimental resu...

Oxygen-vacancy dipoles and dimers in CaF2 crystals have been studied ab initio at DFT level and with the shell model using pair potentials. The calculated dipole reorientation barrier is 0.64 eV and the activation energy for diffusion of the dipoles is 1.61 eV. Optical absorption of O2--VA dipole have been calculated with TD DFT and identified with experimental absorption bands, which appeared ...

Part 2 reviews the materials properties of photonic materials, such as structure (chemical bonds) and electrical conductivity (bands) in Group IV and III-V compound/alloy semiconductors. The correlation of the principal quantum number with optical, thermal and mechanical properties is examined. The definition of effective mass qualifies the energy-wavenumber dispersion relation for direct or in...

The Kronig-Penney model is typically used to compute the band structure and bound states of a periodic crystal. While the model allows analytical solutions, it does so by simplifying the potential to a periodic square potential. We present a method of using transfer matrices to compute energy bands in a 1-Dimensional lattice. This method does not involve the simplification required by the Kroni...

We show that Mach bands and a number of other low-level brightness illusions can be accounted for by assuming that the perceptual system performs simple Bayesian inference using a Gaussian image prior with noisy retinal gangion cells. This theory accounts for phenomena which have proven problematic for simple energy-based and lateral-interaction models while avoiding the complexities of mid-lev...