Séminaire du Vendredi 16 septembre 2011 à 10h30

ULTRACOLD FERMIONS IN OPTICAL LATTICES UNDER ARTIFICIAL MAGNETIC FIELDS

IMPMC, Université P. et M. Curie, 4, Place Jussieu, 75005 Paris

Salle de Conférence (401)

4ème étage

Tour 23

Couloir 22-23
  

Cristiane MORAIS SMITH (Institute for Theoretical Physics, Utrecht University, the Netherlands)

In this talk, I first discuss an experimental set-up recently proposed by us, which allows for the realization of a "staggered gauge field" in a 2D square optical lattice. When the system is loaded with a mixture of bosons and fermions, several features of the high-Tc phase diagram can be reproduced. Starting from a DDW phase, unconventional superconductivity with features of the RVB state is obtained for a certain range of parameters.
In the second part, fermions in a honeycomb lattice in the presence of magnetic field and spin-orbit interactions will be considered. The single-particle spectrum of this system has a fractal structure, which is known as the Hofstadter butterfly. We study the effects of spin-orbit interactions and Zeeman splitting on this spectrum. When combined with the usual magnetic field, this interaction may lead to spin-imbalanced topological phases, where there is quantized charge and spin transport. If instead a Rashba spin-orbit
interaction is considered, we find that complex chiral spin structures may be generated.

[1] A. Hemmerich and C. Morais Smith, Phys. Rev. Lett. 99, 113002 (2007).
[2] Lih-King Lim, A. Hemmerich, and C. Morais Smith, Phys. Rev. Lett. 100, 130402 (2008).
[3] Lih-King Lim, A. Hemmerich, and C. Morais Smith, Phys. Rev. A 81, 023404 (2010).
[4] Lih-King Lim, A. Lazarides, A. Hemmerich, and C. Morais Smith, EPL 88, 36001 (2009) and Phys. Rev. A 82, 013616 (2010).
[5] N. Goldman, W. Beugeling, and C. Morais Smith, arXiv:1104.0643 (2011).
[6] D. Makogon, I. B. Spielman, and C. Morais Smith, arXiv: 1007.0782

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