Brand ao, FGSL;
Oppenheim, J;
Strelchuk, S;
(2012)
When does noise increase the quantum capacity?
Physical Review Letters
, 108
(4)
, Article 040501. 10.1103/PhysRevLett.108.040501.
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Abstract
Superactivation is the property that two channels with zero quantum capacity can be used together to yield a positive capacity. Here we demonstrate that this effect exists for a wide class of inequivalent channels, none of which can simulate each other. We also consider the case where one of two zero-capacity channels is applied, but the sender is ignorant of which one is applied. We find examples where the greater the entropy of mixing of the channels, the greater the lower bound for the capacity. Finally, we show that the effect of superactivation is rather generic by providing an example of superactivation using the depolarizing channel.
| Type: | Article |
|---|---|
| Title: | When does noise increase the quantum capacity? |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1103/PhysRevLett.108.040501 |
| Publisher version: | http://link.aps.org/doi/10.1103/PhysRevLett.108.04... |
| Language: | English |
| Additional information: | © 2012 American Physical Society |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1362131 |
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