Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 9: Quantum Liquids, Miscellaneous 1
TT 9.9: Vortrag
Montag, 11. März 2013, 11:45–12:00, H21
Topologically nontrivial and nearly flat bands arising through orbital degrees of freedom — •Maria Daghofer, Stefanos Kourtis, Jörn W.F. Venderbos, and Jeroen van den Brink — IFW Dresden
We discuss models, where electronic correlations can induce
topologically nontrivial electronic states. In particular, we focus on
a three-orbital model for t2g orbitals on a triangular
lattice [1]. Near half filling, onsite Coulomb repulsion and Hund’s rule
coupling induce a non-coplanar magnetic phase where electronic bands
are topologically nontrivial and can become very flat [2]. Such
topologically nontrivial bands with reduced dispersion have been
argued [3-5] to support a lattice analog of fractional quantum-Hall states,
fractional Chern-insulator (FCI) states, that arise in the absence of a magnetic
field. We discuss the competition of FCI states with a charge density
wave depending on properties of the nearly flat band [6].
[1] J. W. Venderbos, M. Daghofer, and J. van den Brink,
Phys. Rev. Lett. 107, 116401 (2011)
J.W.F. Venderbos, S. Kourtis, J. van den Brink, and M. Daghofer, Phys. Rev. Lett. 108, 126405 (2012)
T. Neupert, L. Santos, C. Chamon, and C. Mudry,
Phys. Rev. Lett. 106, 236804 (2010)
K. Sun, Z. Gu, H. Katsura, and S. D. Sarma, Phys. Rev. Lett. 106, 236803 (2010)
E. Tang, J.-W. Mei, and X.-G. Wen, Phys. Rev. Lett. 106, 236802 (2010)
S. Kourtis, J.W.F. Venderbos, and M. Daghofer, arXiv:1208.3481