Intrinsic Defects and Plasticity in Charge and Spin Density Waves

Abstract

Plastic deformations — long living intrinsic defects, are currently on agenda in studies of CDW as well as of other Electronic Crystals and of Vortex Lattices in superconductors. The dislocations are supposed to participate in depinning, in narrow band noise generation, in contact structures. The point defects, 2π-solitons as addatoms and vacancies or also as nucleus dislocation loops, compete with electrons as normal carriers. Also they provide a material for the climb of dislocations required for their expansion. Peculiarities of dislocations in DW crystals are related to their ultimate necessity to transfer a normal current into a coherent crystal flow, to an anomalous elastic theory due to long range Coulomb forces, to fast conversion of normal carriers into nucleus dislocations loops, to combined symmetry for the SDW case. Properties of dislocations in all EC at low T are determined by the Coulomb forces and depend on screening facilities of free carriers. In SDW conventional dislocations loose their priority in favor of special topological objects: half — integer dislocations combined with a semi — vortex of a staggered magnetization vector. The coexistence and mutual conversion of electrons and intrinsic defects results in a nonlinear hydrodynamics for two fields: the DW phase and the electric potential, and for two fluids: electrons and point defects.