Dresden 2011 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 59: TR: Topological Insulators 2 (jointly with HL and MA)
TT 59.9: Vortrag
Freitag, 18. März 2011, 12:45–13:00, HSZ 03
Chirality Induced Tilted-Hill Giant Nernst Signal — •Panagiotis Kotetes1, Gerd Schön1,3, Alexander Shnirman2,3, and Georgios Varelogiannis4 — 1Institut für Theoretische Festkörperphysik, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany — 2Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany — 3DFG-Center for Functional Nanostructures (CFN), D-76128 Karlsruhe, Germany — 4Department of Physics, National Technical University of Athens, GR-15780 Athens, Greece
We reveal a novel source of giant Nernst response exhibiting strong non-linear temperature and magnetic field dependence including the mysterious tilted-hill temperature profile observed in a pleiad of materials [1]. The phenomenon can originate either from a topological insulator or from the formation of a chiral order parameter. Particular examples are the Quantum Anomalous Hall state and the chiral d-density wave, respectively. The occurence of this giant thermoelectric response is distinctly different from the usual quasiparticle and vortex Nernst mechanisms. Our picture provides a unified understanding of the anomalous thermoelectricity observed in materials as diverse as hole doped cuprates [1] and heavy-fermion compounds like URu2Si2 [2]. Moreover, fingerprints of this phenomenon could be observed on the surface of several 3D topological insulators.
P. Kotetes and G. Varelogiannis, Phys. Rev. Lett. 104, 106404 (2010).
P. Kotetes, A. Aperis, and G.Varelogiannis, arXiv:1002.2719.