Motifs of periodic modulations are encountered in a variety of natural systems, where at least two rival states are present. In strongly correlated electron systems, such behaviour has typically been associated with competition between short- and long-range interactions, for example, between exchange and dipole-dipole interactions in the case of ferromagnetic thin films. Here we show that spin-...

A set of exact closed-form Bloch-state solutions to the stationary GrossPitaevskii equation are obtained for a Bose-Einstein condensate in a one-dimensional periodic array of quantum wells, i.e. a square-well periodic potential. We use these exact solutions to comprehensively study the Bloch band, the compressibility, effective mass and the speed of sound as functions of both the potential dept...

The discovery of the quantization particle transport in adiabatic pumping cycles periodic structures by Thouless [Phys. Rev. B 27, 6083 (1983)] linked Chern number, a topological invariant characterizing quantum Hall effect two-dimensional electron gases, with topology dynamical systems one dimension. Here, we demonstrate its counterpart for higher-order topology. Specifically, show that crysta...

We prove that a system of discrete two-dimensional 2D in-plane dipoles with four possible orientations, interacting via a three-dimensional 3D dipole-dipole interaction plus a nearest neighbor ferromagnetic term, has periodic striped ground states. As the strength of the ferromagnetic term is increased, the size of the stripes in the ground state increases, becoming infinite, i.e., giving a fer...

The entanglement character including the so-called sudden death effect between atoms in the non-degenerate two photons Tavis-Cummings model is studied by means of concurrence. The results show that the so-called sudden death effect occurs only for some kind of initial states. In other words, the phenomenon is sensitive to the initial conditions. One can expect the resurrection of the original e...

In this paper, we characterize the rotational dynamics and observe rotor-rotor interactions within a crystalline, three-dimensional array of dipolar molecular rotors. The rotating portion of each rotor molecule consists of a dipolar fluorine-substituted phenyl group. The phenyl rotors are connected by acetylene linkages to bulky triphenyl methyl groups which are held rigid in the crystal lattic...

Molecular dynamics simulation of a large protein in explicit water with periodic boundary conditions is extremely demanding in terms of computation time. Consequently, we have sought approximations of the solvent environment that model its important features. Here, we describe our SAPHYR (Shell Approximation for Protein HYdRation) model in which the protein is surrounded by a shell of water mol...

We report the design and experiment of a novel Yagi-Uda dipole array fed by a MS-to-CPS transition. The Yagi-Uda array having one director on the same plane of the dielectric substrate as the driver element shows higher gain (9.1dB) than microstrip patch antennas and a much wider bandwidth (10.3%). The measured front-to-back ratio is about 15dB. This novel design should become an important alte...

An optimal design of a linear antenna array is presented. The antenna array is optimized using a particle swarm optimization based method in order to produce a radiation pattern that has the minimum possible side lobe level and the maximum possible gain at the desired direction. The method has been applied to collinear wire-dipole arrays and seems to be suitable for improving the radiation patt...