Quantum-capacity-approaching codes for the detected-jump channel
- Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore)
- Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada)
- Department of Mathematics and Statistics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada)
The quantum-channel capacity gives the ultimate limit for the rate at which quantum data can be reliably transmitted through a noisy quantum channel. Degradable quantum channels are among the few channels whose quantum capacities are known. Given the quantum capacity of a degradable channel, it remains challenging to find a practical coding scheme which approaches capacity. Here we discuss code designs for the detected-jump channel, a degradable channel with practical relevance describing the physics of spontaneous decay of atoms with detected photon emission. We show that this channel can be used to simulate a binary classical channel with both erasures and bit flips. The capacity of the simulated classical channel gives a lower bound on the quantum capacity of the detected-jump channel. When the jump probability is small, it almost equals the quantum capacity. Hence using a classical capacity-approaching code for the simulated classical channel yields a quantum code which approaches the quantum capacity of the detected-jump channel.
- OSTI ID:
- 21528853
- Journal Information:
- Physical Review. A, Vol. 82, Issue 6; Other Information: DOI: 10.1103/PhysRevA.82.062324; (c) 2010 American Institute of Physics; ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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