Berlin 2018 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 69: Poster: Quantum Systems

DY 69.4: Poster

Donnerstag, 15. März 2018, 15:30–18:00, Poster A

Quantum chaos in undoped graphene with long-range coulomb interaction — •Markus Klug¹, Mathias Scheurer², and Jörg Schmalian^{1, 3} — ¹Affiliation: Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany — ²Department of Physics, Harvard University, Cambridge MA 02138, USA — ³Affiliation: Institute of Solid State Physics, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen, Germany

In the context of thermalization, we investigate the ability of electrons in undoped Graphene in the presence of long-range Coulomb interaction to scramble information. We therefore compute the Lyapunov exponent which represents the inverse time scale describing the exponential growth of certain out-of-time order correlation functions for intermediate times. The Lyapunov exponent λ is determined perturbatively to order O(1/N) where N is the number of fermion flavors. By doing so we are able to investigate the weak α→0 and strong α→∞ coupling regime with α being the fine structure constant determining the electron-electron interaction strength. By restoring N=4 in case of graphene, we find in the strong coupling regime an exponent of order of the recently proposed bound, and for weak coupling a linear dependence on the coupling strength. The conducted analysis provides insights into the sensitiveness of out-of-time order correlators towards physical relaxation processes.