Binary coherent state alphabets can be represented in a two-dimensional Hilbert space. We capitalize this formal connection between the otherwise distinct domains of qubits and continuous variable states to map binary phase-shift keyed coherent states onto the Bloch sphere and to derive their quantum-optimal clones. We analyze the Wigner function and the cumulants of the clones, and we conclude that optimal cloning of binary coherent states requires a nonlinearity above second order. We propose several practical and near-optimal cloning schemes and compare their cloning fidelity to the optimal cloner.
|Journal||Physical Review A (Atomic, Molecular and Optical Physics)|
|Number of pages||11|
|Publication status||Published - 2017|
Bibliographical note©2017 American Physical Society
Mueller, C. R., Leuchs, G., Marquardt, C., & Andersen, U. L. (2017). Optimally cloned binary coherent states. Physical Review A (Atomic, Molecular and Optical Physics), 96(4), . https://doi.org/10.1103/PhysRevA.96.042311