On the Interplay between Disorder and Frustration in 2D Arrays of Superconducting Junctions

Abstract

We present a detailed investigation of the role played by the areal (positional) disorder and by frustration, f, in determining the properties of the 2D arrays of superconducting junctions in the range of large f. Our computer simulations show, as expected, the existence of periodic structures in the energy vs. f plots. However, the amplitude decay of these structures, induced by the areal disorder, is not linear with f. A similar conclusion can be drawn by inspecting the magnetic moment vs. f plots. By means of a non-linear extrapolation, we are able to define a crossover field, fc, beyond which the phases of the junctions appear to be randomly oriented. The value of the crossover field scales almost linearly with the inverse of the degree of disorder, but the slope does not take the universal value, 0.34, previously proposed. The crossover to the glassy phase, with increasing f, simply mirrors the reaching of the saturation value in the continuously increasing width of the distribution of the plaquette current circuitation.

Static properties of classical Josephson junction arrays: models and experimental achievements

“…Providing a reasonable description of the processes occurring in real superconductors implies dealing with disorder. Disorder strongly modifies the previously described pictures [84]. For example, for specific values of frustration the order-disorder phase transition is of first order (e.g.…”

Lower critical field and vortices configuration in 2D superconducting junction arrays

“…Our description however: a) did not take into account the effect of the screening currents, and thus was confmed essentially to a narrow temperature range below the critical temperature, for which the array penetration depth, ~ ,, can be considered infinite; b) was focused on what we may call the (,geometrical, magnetism (*) Paper presented at the ,,VII Congresso SATT., Torino, 4-7 October 1994. of the array, i.e. Through the above approximations it was possible, for example, to study the relevance of the disorder on the properties of the array [2,3]. Through the above approximations it was possible, for example, to study the relevance of the disorder on the properties of the array [2,3].…”