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TT: Fachverband Tiefe Temperaturen

TT 38: Correlated Electrons: Metal-Insulator Transition 1

TT 38.7: Vortrag

Mittwoch, 13. März 2013, 11:00–11:15, H20

Dielectric breakdown of Mott insulators – doublon production and doublon heating — •Martin Eckstein¹ and Philipp Werner² — ¹Max Planck Research Department for Structural Dynamics, University of Hamburg, CFEL — ²University of Fribourg, Switzerland

Using nonequilibrium dynamical mean-field theory, we study the response of a Mott insulator to strong dc electric fields. Previously, the resulting dielectric breakdown of the insulating state has been studied for isolated bulk systems [1]. Remarkably, in this case a quasi-steady current is observed, although the energy of the system is constantly increasing. In this talk, we show that the current in this nonequilibrium quasi-steady state is related to a field-induced doublon-hole creation mechanism [2]. The induced carriers acquire an infinite-temperature distribution, and hence they do not contribute to the current after the initial pair-creation process. This observation allows to obtain a consistent understanding for the effects of high temperature and dissipation in those systems, which is essential for an understanding of bias-induced metal-insulator transitions in correlated systems.
[1] M. Eckstein, T. Oka, and Ph. Werner, Phys. Rev. Lett. 105, 146404 (2010)
M. Eckstein, and Ph. Werner, arXiv:1211.2698.