We review a progress in experiments and theory, elucidating the role of microscopic solitons in quasi-1D electronic systems with a symmetry breaking. The recent interest rises from a discovery of the ferroelectric charge ordering in organic conductors, and from nano-scale tunneling experiments in Charge Density Wave (CDW) materials.
The charge ordering allows to observe several types of solitons in conductivity and permittivity, and solitons bound pairs in optics, in a fruitful comparison with conducting polymers. Internal tunneling in CDWs goes through the channel of amplitude solitons which correspond to the long sought quasi-particle - the spinon. The tunneling experiment also gives an access to the reversible reconstruction of the junction via spontaneous creation of a lattice of phase solitons: a grid of dislocations. Individual solitons have been visually captured in recent STM experiments.
On this basis we extrapolate to a picture of combined topological excitations in general strongly correlated systems: from nearly antiferromagnetic oxides to high gap superconductors.