Seminars & Lectures
| * TITLE | Solitons in strongly correlated electronic systems: the route from one to higher dimensions | ||||||
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| * DATE / TIME | 2009-05-22, 13:00 | ||||||
| * PLACE | #101, Hogil Kim Memorial Bldg. POSTECH | ||||||
| * ABSTRACT | |||||||
| Physics of microscopic solitons in electronic processes was boosted in early 80\'s by experiments on conducting polymers and theories for charge density waves. Its re-entrance in 2000\'s is motivated by the discovery of the ferroelectric charge ordering in organic conductor and by new nano-scale experiments in charge density wave materials. Solitons show up in conductivity, tunnelling spectroscopy, optical absorption. Instantons -- the processes of dynamic conversion of normal electrons into solitons -- are responsible for subgap transitions leading to a pseudogap formation. Recent confirmations for solitons in quasi one-dimensional systems call for studies of more complicated topological excitations in a broad class of strongly correlated systems, from superconductors to Mott-Hubbard states. Theoretically they are found as spin- or charge- roton configurations with charge- or spin- kinks localized in the core, correspondingly for cases of repulsion and attraction. These complex excitations are derived from spinons and holons in D=1 cases. They can be also viewed as nucleus of the melted stripe phase in doped Mott insulators or of the FFLO phase in spin polarized superconductors. | |||||||
