Karl Franzens University Graz
Graz University of Technology
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Karl Franzens University Graz | Graz University of Technology | |
Mott insulators out of equilibrium In the talk I will discuss some theoretical aspects of materials where the origin of insu- lating behaviour is the Coulomb repulsion between electrons. Low-lying excited states in the prototype Hubbard model can be then discussed in terms of doublons and holons. Moreover, the binding of holon and doublons can serve as the mechanism for the metal- insulator transition. At present the pump-probe spectroscopy opens a novel view on the properties of Mott insulators, and in particular it reveals surprisingly fast relaxation to the equilibrium and interesting transient charge response. I will present a theory based on the existence of the holon-doublon exciton and its recombination, which explains the decay in terms of multi-boson emission. |