Memory effects in spin-chain channels for information transmission

Bayat, A ; Sharif University of Technology | 2008

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  1. Type of Document: Article
  2. DOI: 10.1103/PhysRevA.77.050306
  3. Publisher: 2008
  4. Abstract:
  5. We investigate the multiple use of a ferromagnetic spin chain for quantum and classical communications without resetting. We find that the memory of the state transmitted during the first use makes the spin chain a qualitatively different quantum channel during the second transmission, for which we find the relevant Kraus operators. We propose a parameter to quantify the amount of memory in the channel and find that it influences the quality of the channel, as reflected through fidelity and entanglement transmissible during the second use. For certain evolution times, the memory allows the channel to exceed the memoryless classical capacity (achieved by separable inputs) and in some cases it can also enhance the quantum capacity. © 2008 The American Physical Society
  6. Keywords:
  7. Ferromagnetism ; Information services ; Quantum theory ; Information transmission ; Quantum capacity ; Spin chain channels ; Communication channels (information theory)
  8. Source: Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 77, Issue 5 , 2008 ; 10502947 (ISSN)
  9. URL: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.77.050306