FRUSTRATION-INDUCED DISORDER OF FLUX-LINE STRUCTURES IN LAYERED SUPERCONDUCTORS

As an example of a system with competing (frustrated) interactions, we study a model of the spatial arrangement of flux lines in a layered s uperconductor, with the magnetic field parallel with the layers, and i n the limit of strong pinning to the layers. In this approach, we appr oximate the energy-minimization problem by a discrete nonlinear dynami cal system, in which a vortex structure is built up one layer at a tim e. We find a complex variety of metastable states nearly degenerate wi th the ground state, including lattices with unit cells of many layer spacings, and disordered structures which correspond to chaotic trajec tories of the dynamical map. The latter case provides an example of (m etastable) quenched disorder in a model with no intrinsic randomness.