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TT: Fachverband Tiefe Temperaturen

TT 38: Correlated Electrons: Metal-Insulator Transition 1

TT 38.8: Vortrag

Mittwoch, 13. März 2013, 11:30–11:45, H20

Dimensional-crossover-driven Mott transition in the frustrated Hubbard model — •Marcin Raczkowski and Fakher F. Assaad — Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg

We study the Mott transition in a frustrated Hubbard model with next-nearest neighbor hopping at half-filling [1]. The interplay between interaction, dimensionality and geometric frustration closes the one-dimensional Mott gap and gives rise to a metallic phase with Fermi surface pockets. We argue that they emerge as a consequence of remnant one-dimensional Umklapp scattering at the momenta with vanishing interchain hopping matrix elements. Such a mechanism can also account for the pockets observed in the spinless model. In this pseudogap phase, enhanced d-wave pairing correlations are driven by antiferromagnetic fluctuations. Within the adopted cluster dynamical mean-field theory on the 8× 2 cluster and down to our lowest temperatures the transition from one to two dimensions is continuous.
[1] M. Raczkowski and F. F. Assaad, Phys. Rev. Lett. 109, 126404 (2012)