On the complementary quantum capacity of the depolarizing channel
The qubit depolarizing channel with noise parameter $\eta$ transmits an input qubit perfectly with probability $1-\eta$, and outputs the completely mixed state with probability $\eta$. We show that its complementary channel has positive quantum capacity for all $\eta\gt 0$. Thus, we find that there...
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Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften
2017-09-01
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| Series: | Quantum |
| Online Access: | https://quantum-journal.org/q-2017-09-19-28/pdf/ |
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doaj-f4e11e93c2004bb79bffcef46b0f0b6d2020-11-25T01:28:26ZengVerein zur Förderung des Open Access Publizierens in den QuantenwissenschaftenQuantum2521-327X2017-09-0112810.22331/q-2017-09-19-2810.22331/q-2017-09-19-28On the complementary quantum capacity of the depolarizing channelDebbie LeungJohn WatrousThe qubit depolarizing channel with noise parameter $\eta$ transmits an input qubit perfectly with probability $1-\eta$, and outputs the completely mixed state with probability $\eta$. We show that its complementary channel has positive quantum capacity for all $\eta\gt 0$. Thus, we find that there exists a single parameter family of channels having the peculiar property of having positive quantum capacity even when the outputs of these channels approach a fixed state independent of the input. Comparisons with other related channels, and implications on the difficulty of studying the quantum capacity of the depolarizing channel are discussed.https://quantum-journal.org/q-2017-09-19-28/pdf/ |
| collection |
DOAJ |
| language |
English |
| format |
Article |
| sources |
DOAJ |
| author |
Debbie Leung John Watrous |
| spellingShingle |
Debbie Leung John Watrous On the complementary quantum capacity of the depolarizing channel Quantum |
| author_facet |
Debbie Leung John Watrous |
| author_sort |
Debbie Leung |
| title |
On the complementary quantum capacity of the depolarizing channel |
| title_short |
On the complementary quantum capacity of the depolarizing channel |
| title_full |
On the complementary quantum capacity of the depolarizing channel |
| title_fullStr |
On the complementary quantum capacity of the depolarizing channel |
| title_full_unstemmed |
On the complementary quantum capacity of the depolarizing channel |
| title_sort |
on the complementary quantum capacity of the depolarizing channel |
| publisher |
Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften |
| series |
Quantum |
| issn |
2521-327X |
| publishDate |
2017-09-01 |
| description |
The qubit depolarizing channel with noise parameter $\eta$ transmits an input qubit perfectly with probability $1-\eta$, and outputs the completely mixed state with probability $\eta$. We show that its complementary channel has positive quantum capacity for all $\eta\gt 0$. Thus, we find that there exists a single parameter family of channels having the peculiar property of having positive quantum capacity even when the outputs of these channels approach a fixed state independent of the input. Comparisons with other related channels, and implications on the difficulty of studying the quantum capacity of the depolarizing channel are discussed. |
| url |
https://quantum-journal.org/q-2017-09-19-28/pdf/ |
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AT debbieleung onthecomplementaryquantumcapacityofthedepolarizingchannel AT johnwatrous onthecomplementaryquantumcapacityofthedepolarizingchannel |
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