26 research outputs found

    High-field vortices in Josephson junctions with alternating critical current density

    Full text link
    We study long Josephson junctions with the critical current density alternating along the junction. New equilibrium states, which we call the field synchronized or FS states, are shown to exist if the applied field is from narrow intervals centered around equidistant series of resonant fields, HmH_m. The values of HmH_m are much higher than the flux penetration field, HsH_s. The flux per period of the alternating critical current density, ϕi\phi_i, is fixed for each of the FS states. In the mm-th FS state the value of ϕi\phi_i is equal to an integer amount of flux quanta, ϕi=mϕ0\phi_i =m\phi_0. Two types of single Josephson vortices carrying fluxes ϕ0\phi_0 or/and ϕ0/2\phi_0/2 can exist in the FS states. Specific stepwise resonances in the current-voltage characteristics are caused by periodic motion of these vortices between the edges of the junction.Comment: 4 pages, 5 figure

    Maximum supercurrent in Josephson junctions with alternating critical current density

    Full text link
    We consider theoretically and numerically magnetic field dependencies of the maximum supercurrent across Josephson tunnel junctions with spatially alternating critical current density. We find that two flux-penetration fields and one-splinter-vortex equilibrium state exist in long junctions.Comment: 11 pages, 8 figure

    A DNA Methylation Signature of Addiction in T Cells and Its Reversal With DHEA Intervention

    Get PDF
    Previous studies in animal models of cocaine craving have delineated broad changes in DNA methylation profiles in the nucleus accumbens. A crucial factor for progress in behavioral and mental health epigenetics is the discovery of epigenetic markers in peripheral tissues. Several studies in primates and humans have associated differences in behavioral phenotypes with changes in DNA methylation in T cells and brain. Herein, we present a pilot study (n = 27) showing that the T cell DNA methylation profile differentiates persons with a substance use disorder from controls. Intervention with dehydroepiandrosterone (DHEA), previously shown to have a long-term therapeutic effect on human addicts herein resulted in reversal of DNA methylation changes in genes related to pathways associated with the addictive state
    corecore