Dresden 2011 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 61: Quantum Information: Concepts and Methods 4

Q 61.3: Talk

Friday, March 18, 2011, 11:00–11:15, SCH A118

Uncertainty relations and the graph state formalism — •Sönke Niekamp, Matthias Kleinmann, and Otfried Gühne — Fachbereich Physik, Universität Siegen, Walter-Flex-Straße 3, 57068 Siegen

Uncertainty relations not only describe a fundamental concept of quantum mechanics, but also have found application in quantum cryptography and entanglement detection. Entropic uncertainty relations have turned out to be particularly useful. Central questions here are the characterization of observables yielding strong uncertainty relations and the extension to the case of more than two observables. We demonstrate how the stabilizer or graph state formalism can be applied to these problems. For an arbitrary number of qubits we construct measurement bases for which the Maassen-Uffink entropic uncertainty relation is tight. We compare the relative strengths of variance-based and various entropic uncertainty relations for dichotomic anticommuting observables and discuss the generalization to other classes of observables.