Dresden 2011 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 59: TR: Topological Insulators 2 (jointly with HL and MA)
TT 59.5: Vortrag
Freitag, 18. März 2011, 11:30–11:45, HSZ 03
Topological phase transitions in quantum spin Hall lattices — •Dario Bercioux1,2, Nathan Goldman3, and Daniel F. Urban2 — 1Freiburg Institute for Advanced Studies, Albert-Ludwigs-Universität, D-79104 Freiburg, Germany — 2Physikalisches Institut, Albert-Ludwigs-Universitat, D-79104 Freiburg, Germany — 3Center for Nonlinear Phenomena and Complex Systems - Université Libre de Bruxelles (U.L.B.), Code Postal 231, Campus Plaine, B-1050 Brussels, Belgium
Physical phenomena driven by topological properties, such as the quantum Hall effect, have the appealing feature to be robust with respect to external perturbations. Lately, a new class of materials has emerged manifesting their topological properties at room temperature and without the need of external magnetic fields. These topological insulators are band insulators with large spin-orbit interactions and exhibit the quantum spin-Hall (QSH) effect. Here we investigate the transition between QSH and normal insulating phases under topological deformations of a two-dimensional lattice. We demonstrate that the QSH phase present in the honeycomb lattice looses its robustness as the occupancy of extra lattice sites is allowed [1]. Furthermore, we propose a method for verifying our predictions with fermionic cold atoms in optical lattices. In this context, the spin-orbit interaction is engineered via an appropriate synthetic gauge field [2].
[1] D. Bercioux, N. Goldman, and D.F. Urban, arXiv:1007.2056.
[2] N. Goldman et al., arXiv:1011.3909 Phys. Rev. Lett. (2010) in press.