History dependence and aging in a periodic longrange Josephson array
Abstract
History dependence and aging are studied in the lowtemperature glass phase of a longrange periodic Josephson array. This model is characterized by two parameters, the number of wires (2N) and the flux per unit strip (α) in the limit N>∞ and fixed α<<1 the dynamics of the model are described by the set of coupled integral equations, which coincide with those for the p=4 disordered spherical model. Below the glass transition we have solved these equations numerically in a number of different regimes. We observe powerlaw aging after a fast quench with an exponent that decreases rapidly with temperature. After slow cooling to a nottoolow temperature, we see aging characterized by the appearance of a time scale which has a powerlaw dependence on the cooling rate. By contrast, if the array is cooled slowly to very low temperatures, the aging disappears. The physical consequences of these results in different cooling regimes are discussed for future experiment. We also study the structure of the phase space in the lowtemperature glassy regime. Analytically we expect an exponential number of metastable states just below the glasstransition temperature with vanishing mutual overlap, and numerical results indicate that this scenario remains valid down to zero temperature. Thus in this array there is no further subdivision of metastable states. We also investigate the probability to evolve to different states given a starting overlap, and our results suggest a broad distribution of barriers.
 Publication:

Physical Review B
 Pub Date:
 November 1997
 DOI:
 10.1103/PhysRevB.56.11553
 arXiv:
 arXiv:condmat/9701122
 Bibcode:
 1997PhRvB..5611553C
 Keywords:

 64.70.Pf;
 71.55.Jv;
 74.50.+r;
 Glass transitions;
 Disordered structures;
 amorphous and glassy solids;
 Tunneling phenomena;
 point contacts weak links Josephson effects;
 Condensed Matter  Disordered Systems and Neural Networks
 EPrint:
 22 pages, LaTex, 17 PostScript Figures