# Theoretical Physics

**11 October 2012**

**Time:**15:00 to 16:00

**Location:**SR 8.60

Alastair Kay (Oxford)

The monogamy of quantum correlations

By now, we are quite familiar with the idea that quantum correlations are monogamous; the more entangled Alice and Bob are, the less entangled Alice can be with anyone else. Indeed, this is the fundamental concept behind most quantum cryptography schemes. However, how do we make such a statement quantitative? One route, which I will describe in the talk, is by understanding quantum cloning better; if you try and copy a quantum state, the better you make one copy, the worse the other copies have to be. I will also describe an important consequence of this monogamy of correlations - how the classical world (technically, local realism) emerges from the quantum one. The talk is based on the following papers: arXiv:1010.2016, arXiv:1208.5574.

www.maths.ox.ac.uk/people/profiles/alistair.kay

© Copyright Leeds 2011