Relaxation and coarsening dynamics in superconducting arrays

Article

关键词: FRUSTRATED-XY-MODEL;    PHASE-TRANSITIONS;    ORDERING KINETICS;    VORTEX DYNAMICS;    MONTE-CARLO;    TOPOLOGICAL DEFECTS;    CONTINUOUS SYMMETRY;    SQUARE LATTICE;    TEMPERATURE;    QUENCH;   

DOI  :  10.1103/PhysRevB.67.014501

来源: SCIE

【 摘 要 】

We investigate the nonequilibrium coarsening dynamics in two-dimensional overdamped superconducting arrays under zero external current, where Ohmic dissipation occurs on junctions between superconducting islands through uniform resistance. The nonequilibrium relaxation of the unfrustrated array and also of the fully frustrated array, quenched to low-temperature ordered states or quasiordered ones, is dominated by characteristic features of coarsening processes via decay of point and line defects, respectively. In the case of unfrustrated arrays, it is argued that due to finiteness of the friction constant for a vortex (in the limit of large spatial extent of the vortex), the typical length scale grows as l(s)similar tot(1/2) accompanied by the number of point vortices decaying as N(v)similar to1/t. This is in contrast with the case that dominant dissipation occurs between each island and the substrate, where the friction constant diverges logarithmically and the length scale exhibits diffusive growth with a logarithmic correction term. We perform extensive numerical simulations, to obtain results in reasonable agreement. In the case of fully frustrated arrays, the domain growth of Ising-like chiral order exhibits the low-temperature behavior l(q)similar tot(1/z q), with the growth exponent 1/z(q) apparently showing a strong temperature dependence in the low-temperature limit.

【 授权许可】

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