Quantifying non-Gaussianity of quantum-state correlation Academic Article uri icon


  • 2017 American Physical Society. We consider how to quantify non-Gaussianity for the correlation of a bipartite quantum state by using various measures such as relative entropy and geometric distances. We first show that an intuitive approach, i.e., subtracting the correlation of a reference Gaussian state from that of a target non-Gaussian state, fails to yield a non-negative measure with monotonicity under local Gaussian channels. Our finding clearly manifests that quantum-state correlations generally have no Gaussian extremality. We therefore propose a different approach by introducing relevantly averaged states to address correlation. This enables us to define a non-Gaussianity measure based on, e.g., the trace-distance and the fidelity, fulfilling all requirements as a measure of non-Gaussian correlation. For the case of the fidelity-based measure, we also present readily computable lower bounds of non-Gaussian correlation.

published proceedings


altmetric score

  • 0.75

author list (cited authors)

  • Park, J., Lee, J., Ji, S., & Nha, H.

citation count

  • 16

complete list of authors

  • Park, Jiyong||Lee, Jaehak||Ji, Se-Wan||Nha, Hyunchul

publication date

  • November 2017