Solitons in low dimensional electronic systems of synthetic conductors.

LECTURER: Serguei Brazovskii(CNRS & University Paris-Sud, Orsay, France)

TITLE: Solitons in Low Dimesional Electronic Systems of Synthetic Conductors.
 

ABSTRACT:

A vast variety and whole families of “synthetic conductors” have been designed by motivation and for the purpose of obtaining desired electronic and optical properties.  A firework of new physical effects of electronic correlations feeds fundamental experimental and theoretical researches. Diverse phase transitions are commonly observed towards various electronic phases: superconductivity, anti-ferromagnetism, ferroelectricity, charge order, charge- and spin density waves, Mott and Peierls insulators, phases induced by high magnetic and electric fields and by optical pumping. Vulnerability of the broken symmetries gives rise to topological defects like electronic vortices, walls, stripes. The typical low-dimensional architecture of these compounds brings these objects to a microscopic scale giving rise to “solitons” which description will be the major content of this talk.

The solitons are self-localized configurations which shapes explore the ground state degeneracy. The mathematics of exact solutions for many-body models relates these trajectories to profiles of waves’ arrays and of superwaves in the ocean and to pulses in optical fibers. The solitons can be the lowest energy optical excitations or the carriers of charge or/and spins, taking these functions from conventional electrons. The “instantons” appear as processes of dynamic conversion of normal electrons into solitons. In a broad class of strongly correlated systems, beyond the low-dimensionality, the solitons can persist acquiring forms of more complicated topological excitations which give incarnations to long time searched “spinons” and "holons"