Determining Pair Interactions from Structural Correlations

We examine metastable configurations of a two-dimensional system of interacting particles on a quenched random potential landscape and ask how the configurational pair correlation function is related to the particle interactions and the statistical properties of the potential landscape. Understanding this relation facilitates quantitative studies of magnetic flux line interactions in type II superconductors, using structural information available from Lorentz microscope images or Bitter decorations. Previous work by some of us supported the conjecture that the relationship between pair correlations and interactions in pinned flux line ensembles is analogous to the corresponding relationship in the theory of simple liquids. The present paper aims at a more thorough understanding of this relation. We report the results of numerical simulations and present a theory for the low density behavior of the pair correlation function which agrees well with our simulations and captures features observed in experiments. In particular, we find that the resulting description goes beyond the conjectured classical liquid type relation and we remark on the differences.Comment: 7 pages, 6 figures. See also http://rainbow.uchicago.edu/~grier

Quantum Interference in Superconducting Wire Networks and Josephson Junction Arrays: Analytical Approach based on Multiple-Loop Aharonov-Bohm Feynman Path-Integrals

We investigate analytically and numerically the mean-field superconducting-normal phase boundaries of two-dimensional superconducting wire networks and Josephson junction arrays immersed in a transverse magnetic field. The geometries we consider include square, honeycomb, triangular, and kagome' lattices. Our approach is based on an analytical study of multiple-loop Aharonov-Bohm effects: the quantum interference between different electron closed paths where each one of them encloses a net magnetic flux. Specifically, we compute exactly the sums of magnetic phase factors, i.e., the lattice path integrals, on all closed lattice paths of different lengths. A very large number, e.g., up to $10^{81}$ for the square lattice, exact lattice path integrals are obtained. Analytic results of these lattice path integrals then enable us to obtain the resistive transition temperature as a continuous function of the field. In particular, we can analyze measurable effects on the superconducting transition temperature, $T_c(B)$, as a function of the magnetic filed $B$, originating from electron trajectories over loops of various lengths. In addition to systematically deriving previously observed features, and understanding the physical origin of the dips in $T_c(B)$ as a result of multiple-loop quantum interference effects, we also find novel results. In particular, we explicitly derive the self-similarity in the phase diagram of square networks. Our approach allows us to analyze the complex structure present in the phase boundaries from the viewpoint of quantum interference effects due to the electron motion on the underlying lattices.Comment: 18 PRB-type pages, plus 8 large figure

Coordination-polymeric nanofibers and their field-emission properties a

10.1002/marc.200900230Macromolecular Rapid Communications30151356-1361MRCO

A simple technique for dynamic optical tweezers using mirror on a vibrating membrane

10.1117/12.678735Proceedings of SPIE - The International Society for Optical Engineering6326-PSIS

L X-ray production cross sections of medium Z elements by 4He ion impact

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms136-138184-188NIMB

Experimental L-shell X-ray production and ionization cross sections for proton impact

10.1006/adnd.1994.1005Atomic Data and Nuclear Data Tables561159-210ADND

Micro-opto-mechanical devices made of carbon nanotubes arrays

Diffusion and Defect Data Pt.B: Solid State Phenomena121-123PART 1517-520DDBP

Photocurrent characteristics of individual GeSe2 nanobelt with Schottky effects

10.1063/1.4823779Journal of Applied Physics11413-JAPI

Enhanced field emission from CuO nanowire arrays by in situ laser irradiation

10.1063/1.2818096Journal of Applied Physics10211-JAPI