Hannover 2010 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 11: Quantum Information: Concepts and Methods II

Q 11.10: Talk

Monday, March 8, 2010, 18:45–19:00, E 214

Area laws for thermal free fermions — •Holger Bernigau and Jens Eisert — University of Potsdam, 14476 Potsdam, Germany

Physical interactions in quantum many-body systems are typically local: Individual constituents interact mainly with their few nearest neighbors. This locality of interactions is inherited by a decay of correlation functions, but also reflected by scaling laws of correlation or entanglement measures: They satisfy an "area law" if the they merely grow like the boundary area of the subregion, and not like its volume, in sharp contrast with an expected extensive behavior. In this talk, we will investigate the scaling of the mutual information for thermal states of free fermionic lattice systems, and will discuss an exact formula for the asymptotic scaling, including all prefactors. Ideas of Toeplitz determinants applied to thermal states will be mentioned. We will finally briefly discuss implications of such results to the simulatability of such quantum systems.