Correlations due to localization in quantum eigenfunctions of disordered microwave cavities

Non-universal correlations due to localization are observed in statistical properties of experimental eigenfunctions of quantum chaotic and disordered microwave cavities. Varying energy {E} and mean free path {l} enable us to experimentally tune from localized to delocalized states. Large level-to-level Inverse Participation Ratio (IPR I_{2}) fluctuations are observed for the disordered billiards, whose distribution is strongly asymmetric about . The density auto-correlations of eigenfunctions are shown to decay exponentially and the decay lengths are experimentally determined. All the results are quantitatively consistent with calculations based upon nonlinear sigma-models.Comment: 4 pages, LaTex, 5 .jpg figures. This paper with 5 embedded postscript figures available (PS,PDF) at http://sagar.physics.neu.edu/preprints

From chaos to disorder: Statistics of the eigenfunctions of microwave cavities

We study the statistics of the experimental eigenfunctions of chaotic and disordered microwave billiards in terms of the moments of their spatial distributions, such as the Inverse Participation Ratio (IPR) and density-density auto-correlation. A path from chaos to disorder is described in terms of increasing IPR. In the chaotic, ballistic limit, the data correspond well with universal results from random matrix theory. Deviations from universal distributions are observed due to disorder induced localization, and for the weakly disordered case the data are well-described by including finite conductance and mean free path contributions in the framework of nonlinear sigma models of supersymetry.Comment: 5 pages + 2 JPG figure

Matching Multiple Patterns From Right to Left

We address the problem of matching multiple pattern strings against a text string. Just as the Aho-Corasick algorithm generalizes the Knuth-Morris-Pratt single-pattern algorithm to handle multiple patterns, we exhibit two generalizations of the Boyer-Moore algorithm to handle multiple patterns. In order to obtain worst-case time bounds better than quadratic, our algorithms remember some of the previous history of the matching

Comments on "Vortex Glass and Lattice Melting Transitions in a YNi_2B_2C Single Crystal"

Recently, Mun et.al. (Phys. Rev. Lett., 76, 2790 (1996)) have published their results on single crystal YNi_2B_2C, claiming that their experimental observations can be explained in terms of formation of Vortex Glass and Lattice melting. Our experiments, carried out on samples obtained from the SAME source, reveal a much richer phase diagram and span wider regions of experimental parameter space than Mun et. al. that encompasses most of their observations. We speculate that this material has anomalous intrinsic properties and the results cannot be explained by simple models about the flux lattice.Comment: 1 page, LaTeX type, 1 PostScript figure, Uses PRABIB.STY file, 600 dpi PS file available at http://sagar.physics.neu.edu/preprints.html To appear in Physical Review Letter

Proper ferroelastic phase transitions in thin epitaxial films with symmetry-conserving and symmetry-breaking misfit strains

We study how the ferroelastic domain structure sets in in an epitaxial film of a material with second order proper ferroelastic transition. The domain structures considered are similar to either $a_{1}/a_{2}/a_{1}/a_{2}$ or $c/a/c/a$ structures in perovskite ferroelectrics. If the "extrinsic" misfit strain, not associated with the transition, does not break the symmetry of the high-temperature phase, the phase transition in the film occurs at somewhat lower temperature compared to the bulk. The loss of stability then occurs with respect to a sinusoidal strain wave, which evolves into the domain structure with practically the same geometry and approximately the same period. In the presence of the symmetry-breaking component of the misfit strain ("extrinsic" misfit) the character of the phase transition is qualitatively different. In this case it is a {\em topological} transition between single-domain and multi-domain states, which starts from a low density of the domain walls.Comment: 7 pages, 2 figures, REVTeX 3.

Kaempferol-Phospholipid Complex: Formulation, and Evaluation of Improved Solubility, In Vivo Bioavailability, and Antioxidant Potential of Kaempferol

The current work describes the formulation and evaluation of a phospholipid complex of kaempferol toenhance the latter’s aqueous solubility, in vitro dissolution rate, in vivo antioxidant and hepatoprotectiveactivities, and oral bioavailability. The kaempferol-phospholipid complex was synthesized using a freeze-drying method with the formulation being optimized using a full factorial design (32) approach. The resultsinclude the validation of the mathematical model in order to ascertain the role of specific formulation andprocess variables that contribute favorably to the formulation’s development. The final product wascharacterized and confirmed by Differential Scanning Calorimetry (DSC), Fourier Transform InfraredSpectroscopy (FTIR), Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), and Powder X-rayDiffraction (PXRD) analysis. The aqueous solubility and the in vitro dissolution rate were enhanced comparedto that of pure kaempferol. The in vivo antioxidant properties of the kaempferol-phospholipid complex wereevaluated by measuring its impact on carbon tetrachloride (CCl4)-intoxicated rats. The optimizedphospholipid complex improved the liver function test parameters to a significant level by restoration of allelevated liver marker enzymes in CCl4-intoxicated rats. The complex also enhanced the in vivo antioxidantpotential by increasing levels of GSH (reduced glutathione), SOD (superoxide dismutase), catalase anddecreasing lipid peroxidation, compared to that of pure kaempferol. The final optimized phospholipidcomplex also demonstrated a significant improvement in oral bioavailability demonstrated by improvementsto key pharmacokinetic parameters, compared to that of pure kaempferol

Superfluid density in the underdoped YBa_2Cu_3O_{7-x}: Evidence for d-density wave order of pseudogap

The investigation of the penetration depth \lambda_{ab}(T,p) in YBa_2Cu_3O_{7-x} crystals allowed to observe the following features of the superfluid density n_s(T,p)\propto \lambda_{ab}^{-2}(T,p) as a function of temperature T<Tc/2 and carrier concentration 0.078\le p\le 0.16 in CuO_2 planes: (i) n_s(0,p) depends linearly on p, (ii) the derivative |dn_s(T,p)/dT|_{T\to 0} depends on p slightly in the optimally and moderately doped regions (0.10<p\le 0.16); however, it rapidly increases with p further lowering and (iii) the latter finding is accompanied by the linear low-temperature dependence [-\Delta n_s(T)]\propto T changing to [-\Delta n_s(T)]\propto \sqrt{T}. All these peculiarities can be treated in the framework of d-density wave scenario of electronic processes in underdoped high-Tc materials.Comment: 4 pages, 5 figures. To be published in Phys.Rev.Let

Alternative approach to all-angle negative refraction in two-dimensional photonic crystals

We show that with an appropriate surface modification, a slab of photonic crystal can be made to allow wave transmission within the band gap. Furthermore, negative refraction and all-angle-negative-refraction (AANR) can be achieved by this surface modification in frequency windows that were not realized before in two-dimensional photonic crystals [C. Luo et al, Phys. Rev. B 65, 201104 (2002)]. This approach to AANR leads to new applications in flat lens imaging. Previous flat lens using photonic crystals requires object-image distance u+v less than or equal to the lens thickness d, u+v d. Our approach can be used to design flat lens with u+v=sd with s>>1, thus being able to image large and/or far away objects. Our results are confirmed by FDTD simulations.Comment: 5 pages, 9 eps figs in RevTex forma