Quasi-inversion of qubit channels

Karimipour, V ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1103/PhysRevA.101.032109
  3. Publisher: American Physical Society , 2020
  4. Abstract:
  5. In general quantum operations, or quantum channels cannot be inverted by physical operations, i.e., by completely positive trace-preserving maps. An arbitrary state passing through a quantum channel loses its fidelity with the input. Given a quantum channel E, we discuss the concept of its quasi-inverse as a completely positive trace-preserving map Eqi which when composed with E increases its average input-output fidelity in an optimal way. The channel Eqi comes as close as possible to the inverse of a quantum channel. We give a complete classification of such maps for qubit channels and provide quite a few illustrative examples. © 2020 American Physical Society
  6. Keywords:
  7. Quantum channel ; Quantum communication ; Quantum entanglement ; Qubits ; Arbitrary state ; Complete classification ; Completely positive ; Input-output ; Quantum operations ; Quasi-inverse ; Qubit channels ; Trace-preserving maps ; Communication channels (information theory)
  8. Source: Physical Review A ; Volume 101, Issue 3 , 2020
  9. URL: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.101.032109