Dresden 2014 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 79: Correlated Electrons - Poster Session

TT 79.42: Poster

Mittwoch, 2. April 2014, 15:00–19:00, P2

Energy dynamics in the Heisenberg-Kitaev chain — •Robin Steinigeweg and Wolfram Brenig — Institute for Theoretical Physics, Technical University Braunschweig, Germany

Spin liquids are realized by the Kitaev model and by the Heisenberg model in one dimension, with a finite-temperature dynamics only partially resolved despite the integrability of both models. We make an essential step forward by studying the dynamics in the Heisenberg-Kitaev chain as a model of two competing spin liquids. Using analytical and numerical approaches within linear response, we show the emergence of purely ballistic energy transport at all integrable points, which manifests as pronounced Drude weights and low-frequency suppression of regular contributions. Varying several model parameters including exchange-coupling strength, ratio, and anisotropy as well as magnetic field, we find extended quantum chaotic regions with vanishing Drude weights and well-defined DC contributions. In the vicinity of the Kitaev model, we find clear signatures of the topological gap in the response function.