## Abstract

Continuing our earlier work (quant-ph/0401060), we give two alternative proofs of the result that a noiseless qubit channel has identification capacity 2: the first is direct by a “maximal code with random extension” argument, the second is by showing that 1 bit of entanglement (which can be generated by transmitting 1 qubit) and negligible (quantum) communication has identification capacity 2. This generalizes a random hashing construction of Ahlswede and Dueck: that 1 shared random bit together with negligible communication has identification capacity 1.
We then apply these results to prove capacity formulas for various quantum feedback channels: passive classical feedback for quantum– classical channels, a feedback model for classical–quantum channels, and “coherent feedback” for general channels.

Translated title of the contribution | Identification Via Quantum Channels in the Presence of Prior Correlation and Feedback |
---|---|

Original language | English |

Title of host publication | General Theory of Information Transfer and Combinatorics |

Editors | R Ahlswede |

Publisher | Springer |

Pages | 486 - 504 |

Number of pages | 19 |

ISBN (Print) | 9783540462446 |

Publication status | Published - 2006 |