INCOMMENSURATENESS EFFECTS IN A LATTICE GINZBURG-LANDAU MODEL

This paper discusses the effect of magnetic translational symmetry on the vortex structure in superconducting crystals with a large basis in artificial Josephson media (regular lattices of superconducting clust ers) prepared with opal as the base material. For external magnetic fi elds lower than the upper critical field, the lattice Ginzburg-Landau model reduces to the two-dimensional Frenkel'-Kontorova model which in some cases is exactly solvable, in which the crystal lattice plays th e role of an ''hard sublattice'' while the deformable vortex lattice p lays the role of a ''soft sublattice.'' It is shown that static shear waves in the vortex lattice are solutions to the two-dimensional sine- Gordon equation with an additional condition of incompressibility impl ied by flux quantization. The pinning energy is found as a function of the magnetic field, nearness to the transition line, and the crystal lattice constant. (C) 1997 American Institute of Physics.