Coarse graining the phase space of N qubits

@article{Matteo2017CoarseGT,
  title={Coarse graining the phase space of N qubits},
  author={Olivia Di Matteo and Luis L. S{\'a}nchez-Soto and Gerd Leuchs and Markus Grassl},
  journal={Physical Review A},
  year={2017},
  volume={95},
  pages={022340}
}
We develop a systematic coarse-graining procedure for systems of N qubits. We exploit the underlying geometrical structures of the associated discrete phase space to produce a coarse-grained version with reduced effective size. Our coarse-grained spaces inherit key properties of the original ones. In particular, our procedure naturally yields a subset of the original measurement operators, which can be used to construct a coarse discrete Wigner function. These operators also constitute a… 

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