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

Spontaneous bilateral Achilles tendon rupture in a patient treated with oral levofloxacin

A case of bilateral rupture of the Achilles tendon in a patient treated with levofloxacin for cystitis is reported. A 76-year-old woman suddenly developed painful ankles one day after levofloxacin treatment. Drug therapy was switched to amoxicillin/clavulanate on the fourth day. Sonography revealed a serious condition of tendinosis with complete bilateral full-thickness rupture on day 6. Tendons were both repaired in the same surgical session. Pathological anatomy of the specimens reported fatty tissue lobules with panniculitis and histiocytosis. Ankles were immobilized postoperatively with a plaster cast. Achilles tendon rupture may occur as an adverse side effect of short-term use of levofloxacin, a fluoroquinolone antibiotic. This adverse effect is a rare and poorly understood complication of this antibiotic therapy. A review of the literature is provided