Dynamics of gap solitons in a dipolar Bose-Einstein condensate on a three-dimensional optical lattice

We suggest and study the stable disk- and cigar-shaped gap solitons of a dipolar Bose-Einstein condensate of $^{52}$Cr atoms localized in the lowest band gap by three optical-lattice (OL) potentials along orthogonal directions. The one-dimensional version of these solitons of experimental interest confined by an OL along the dipole moment direction and harmonic traps in transverse directions is also considered. Important dynamics of (i) breathing oscillation of a gap soliton upon perturbation and (ii) dragging of a gap soliton by a moving lattice along axial $z$ direction demonstrates the stability of gap solitons. A movie clip of dragging of three-dimensional gap soliton is included.Comment: To see the dragging movie clip please download sourc

Dynamics of quasi-one-dimensional bright and vortex solitons of a dipolar Bose-Einstein condensate with repulsive atomic interaction

By numerical and variational analysis of the three-dimensional Gross-Pitaevskii equation we study the formation and dynamics of bright and vortex-bright solitons in a cigar-shaped dipolar Bose-Einstein condensate for large repulsive atomic interactions. Phase diagram showing the region of stability of the solitons is obtained. We also study the dynamics of breathing oscillation of the solitons as well as the collision dynamics of two solitons at large velocities. Two solitons placed side-by-side at rest coalesce to form a stable bound soliton molecule due to dipolar attraction.Comment: To obtain the included video clips S1, S2, S3 and S4, please download sourc

REGIONAL COMPETITIVE POSITION OF PORK INDUSTRY

In the recent past U.S. pork industry experienced geographical shifts in its production and processing. Some geographical areas have competitive advantages over the areas in raising pigs. Costs of raising pigs vary by type and size of operations, and other location specific factors. We used enterprise budgeting approach to estimate the profitability of representative feeder to finishing operations in different geographical regions in U.S. We obtained data from the United States Department of Agriculture databases, costs and returns survey and various university sources. The cost differences were not due to the unit prices of inputs but were largely driven by the differences in their efficiencies. Overhead costs varies by locations and size of operation. Pork feeding operations of all sizes operate at a loss if we account for all the cash expenses and opportunity costs given the prices of all inputs and output. However, producers got positive profits over the variable costs. The Eastern Corn belt regions' pork producers reap the highest operating profit ($1,861 per 100 hogs) followed by the Western Corn Belt region and the West region ($1,661). The results of production systems analyses as outlined here suggest that smaller firms have limited ability to compete with larger firms on the basis of cost of production. The key to keeping hog business competitive is higher production efficiency. Feed, labor, and building and equipment efficiencies were potential means of cutting production costs. Smaller producers who do not attain strong efficiencies in production are at a disadvantage relative to larger producers.Livestock Production/Industries,

Universal scaling in BCS superconductivity in two dimensions in non-s waves

The solutions of a renormalized BCS model are studied in two space dimensions in $s$, $p$ and $d$ waves for finite-range separable potentials. The gap parameter, the critical temperature $T_c$, the coherence length $\xi$ and the jump in specific heat at $T_c$ as a function of zero-temperature condensation energy exhibit universal scalings. In the weak-coupling limit, the present model yields a small $\xi$ and large $T_c$ appropriate to those for high-$T_c$ cuprates. The specific heat, penetration depth and thermal conductivity as a function of temperature show universal scaling in $p$ and $d$ waves.Comment: 11 pages, LATEX, 4 postscript figures embedded using eps

Two-component gap solitons with linear interconversion

We consider one-dimensional solitons in a binary Bose-Einstein condensate with linear coupling between the components, trapped in an optical-lattice potential. The inter-species and intra-species interactions may be both repulsive or attractive. Main effects considered here are spontaneous breaking of the symmetry between components in symmetric and antisymmetric solitons, and spatial splitting between the components. These effects are studied by means of a variational approximation and numerical simulations.Comment: 4 pages, 9 figure