Berlin 2005 – wissenschaftliches Programm

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Q: Quantenoptik und Photonik

Q 34: Quanteninformation I

Q 34.4: Vortrag

Dienstag, 8. März 2005, 12:45–13:00, HU Audimax

No Disturbance without Measurement — •Dennis Kretschmann, Dirk Schlingemann, and Reinhard F. Werner — Institut für Mathematische Physik, Technische Universität Braunschweig, www.imaph.tu-bs.de/qi

In this contribution we focus on the trade-off between the amount of information that can be sent through a quantum channel and the degree of disturbance caused by interaction with the environment. This trade-off lies at the heart of quantum mechanics, and has given rise to the well-known slogan ‘no measurement without disturbance’. Here we will chiefly be concerned with the converse problem: given a quantum channel that releases (almost) no information to the environment, we show that (almost) all the information can be retrieved from the channel, and give explicit bounds. We present several different formulations of this trade-off, which are adapted to different physical setups. In particular, we relate these concepts to the coherentification protocol which Igor Devetak recently applied in his proof of the quantum channel coding theorem.