printlogo
http://www.ethz.ch/index_EN
International Workshop on Quantum Information Processing
 
print
  

QIP 2010 at

ETH Life

The daily web-journal of ETH Zurich:

"Lifting the big veil"

"Nach dem grossen Schleier lüften"

18.01.2010

QIP 2010 at the

Swiss Radio DRS

Echo der Zeit

from Monday Jan 18, 2010

in German, Link >>

(Real Player recommended)

chocolate


pdf files of
Programme Booklet >>
and
Abstracts of all Talks >>

You will receive a hard copy of these files at the registration desk.

Sponsors

Pauli Center for Theoretical Studies

pauliohne


The Swiss National Science Foundation

snflogo


ETH Zurich (Computer Science and Physics Department)

ethlogo


Quantum Science and Technology

qsitmitschrift


CQT Singapore

cqtlogo


QAP European Project

qaplogo3


Sandia National Laboratories

sandia


Institute for Quantum Computing

finaliqc


id Quantique

3rdideequantique

Super-duper-activation of the zero-error quantum capacity

Toby Cubitt, Bristol

joint work with Jianxin Chen, Aram Harrow, and Graeme Smith

The zero-error classical capacity of a quantum channel is the asymptotic rate at which it can be used to send classical bits perfectly, so that they can be decoded with zero probability of error. The study of zero-error capacities dates right back to Shannon and the early days of information theory. We show that there exist pairs of quantum channels, neither of which individually have any zero-error capacity whatsoever (even if arbitrarily many uses of the channels are available), but such that access to even a single copy of both channels allows classical information to be sent perfectly reliably. In other words, we prove that the zero-error classical capacity can be superactivated. This result is the first example of superactivation of a classical capacity of a quantum channel.

We further strengthen this result to show that there exist pairs of channels, neither of which have any zero-error classical capacity (as before), yet for which access to one copy of the joint channel even allows far more delicate quantum information to be transmitted perfectly. This subsumes the first result, and also implies that the quantum zero-error capacity can be superactivated. But it is strictly stronger than either of these. Indeed, this is the strongest conceivable form of superactivation, and nothing similar is possible for standard Shannon capacities of quantum channels or for zero-error capacities of classical channels.

 

Wichtiger Hinweis:
Diese Website wird in älteren Versionen von Netscape ohne graphische Elemente dargestellt. Die Funktionalität der Website ist aber trotzdem gewährleistet. Wenn Sie diese Website regelmässig benutzen, empfehlen wir Ihnen, auf Ihrem Computer einen aktuellen Browser zu installieren. Weitere Informationen finden Sie auf
folgender Seite.

Important Note:
The content in this site is accessible to any browser or Internet device, however, some graphics will display correctly only in the newer versions of Netscape. To get the most out of our site we suggest you upgrade to a newer browser.
More information

© 2015 ETH Zürich | Imprint | Disclaimer | 5 January 2010
top