Reeb, David

Date: Thursday, October 9, 2014
Time: 11:00
Place: ETH Zurich, Hönggerberg, HIT E 41.1
Host:  Volkher Scholz

Combatting quantum noise

David Reeb
TU Munich, Germany

We introduce continuous-time versions of the quantum capacity, which are suited to quantify information storage in a quantum memory when active control is available. We compute this "subdivision capacity" for several classes of available control operations. For the case of unitary control, we show by entropic methods that the subdivision capacity of unital noise channels drops to zero exponentially fast in time, which is markedly different from non-unital noise channels (since they can evacuate entropy from the memory). For non-unital noise, we still prove by non-entropic methods an exponential upper bound on the storage time of quantum information, which resolves a conjecture from arXiv:1301.1995.

Joint work with A. Müller-Hermes and M. Wolf (arXiv:1310.2856) and P. Vrana (in preparation)