Sliding of a vortex solid with self-generated randomness in a frustrated Josephson junction array

Abstract

A class of Josephson junction arrays under external magnetic field with anisotropic Josephson couplings realizes a gapless band of metastable vortex solid states with self-generated randomness. Each of the metastable states is characterized by a frozen pattern of transverse undulation of vortex stripes which run along the direction of weaker Josephson coupling. The vortex stripes can slide into the direction of stronger Josephson coupling even at zero temperature, eliminating the pinning effects of the underlying lattice structure of the array, but blocked into the direction of weaker coupling. Because of the sliding of the vortex matter, the phase of superconducting order parameter remain disordered at macroscopic level even at zero temperature. This is an extremely strong version of the spin-chirality decoupling which should be manifested in electric transport properties.