We present a model compound with spin-1/2 frustrated square lattice, in which three ferromagnetic (F) interactions and one antiferromagnetic (AF) compet. Considering the effective spin-1 formed by dominant F dimer, this lattice can be mapped to spatially anisotropic triangular lattice. The magnetization curve exhibits gapped behavior indicative of one-dimensional (1D) AF correlation. In field-i...

We report on the two-dimensional gap-soliton nature of exciton-polariton macroscopic coherent phases (PMCP) in a square lattice with a tunable amplitude. The resonantly excited PMCP forms close to the negative mass M point of the lattice band structure with energy within the lattice band gap and its wave function localized within a few lattice periods. The PMCPs are well described as gap solito...

Binary complex plasmas consist of microparticles two different species and can form two-dimensional square lattices under certain conditions. The dispersion relations the lattice waves are derived for longitudinal transverse in-plane modes, assuming that out-of-plane mode is suppressed by strong vertical confinement. results compared with spectra obtained in Langevin dynamics simulations. Furth...

We present an effective theory for the Bloch functions of a two-dimensional square lattice near a quadratic degeneracy point. The degeneracy is protected by the symmetries of the crystal, and breaking these symmetries can either open a band gap or split the degeneracy into a pair of linear degeneracies that are continuable to Dirac points. A degeneracy of this type occurs between the second and...

In this paper two –dimensional square shaped photonic crystal ring resonator based NOT logic gate is proposed. The numerical, structural, theoretical analysis is performed using 2D-FDTD method where simulation is done through an optical switch. This switch is composed of nonlinear PCRR and T-type waveguide. The dielectric rods used in air is of Indium Phosphide with refractive index of 3.1. Ban...

It is known that folding a protein chain into a cubic lattice is an NP-complete problem. We consider a seemingly easier problem: given a three-dimensional (3D) fold of a protein chain (coordinates of its C(alpha) atoms), we want to find the closest lattice approximation of this fold. This problem has been studied under names such as "lattice approximation of a protein chain", "the protein chain...

A finite-difference frequency-domain method based on the Yee's cell is utilized to analyze the band diagrams of two-dimensional photonic crystals with square or triangular lattice. The differential operator is replaced by the compact scheme and the index average scheme is introduced to deal with the curved dielectric interfaces in the unit cell. For the triangular lattice, the hexagonal unit ce...