Regensburg 2013 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 14: Correlated Electrons: Low-Dimensional Systems - Models 2
TT 14.13: Vortrag
Montag, 11. März 2013, 18:15–18:30, H9
Adiabatic loading of one-dimensional SU(N) alkaline earth fermions in optical lattices — •Lars Bonnes1, Hazzard Kaden2, Salvatore Manmana2, Ana Maria Rey2, and Stefan Wessel3 — 1Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck, Austria — 2JILA, NIST and University of Colorado, and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA — 3Institute for Theoretical Solid State Physics, JARA-FIT, and JARA-HPC, RWTH Aachen University, Otto-Blumenthal-Str. 26, D-52056 Aachen, Germany
Hubbard models with effective SU(N) symmetry have successfully been implemented in ultra-cold alkaline earth experiments. This paves the way towards the regime of exotic magnetism emerging in the low-energy sector but requiring ultra-cool temperatures below the superexchange scale. Loading N>2 fermions onto optical lattices, however, provides a cooling benefit with respect to conventional SU(2) fermions emerging from the N-scaling of the entropy. Hence the accessible temperature regime is lowered drastically, as already observed in recent experiments by Tanaka et al. We present large-scale quantum Monte Carlo simulations combined with series expansion results to quantitatively study the Pomeranchuk cooling effect for SU(N) fermions loaded onto a one-dimensional optical lattice and find a significant temperature decrease as N is increased. Furthermore, we examine the crossover behavior to the magnetic regime and show that the systems do not only become cooler but also become closer to the magnetic (ground-state) regime with respect to the appearance of magnetic correlations.