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arXiv · 2109.14353

Quantifying non-Gaussianity of a quantum state by the negative entropy of quadrature distributions

Jiyong Park·Jaehak Lee·Kyunghyun Baek·Hyunchul Nha
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Abstract

We propose a non-Gaussianity measure of a multimode quantum state based on the negentropy of quadrature distributions. Our measure satisfies desirable properties as a non-Gaussianity measure, i.e., faithfulness, invariance under Gaussian unitary operations, and monotonicity under Gaussian channels. Furthermore, we find a quantitative relation between our measure and the previously proposed non-Gaussianity measures defined via quantum relative entropy and the quantum Hilbert-Schmidt distance. This allows us to estimate the non-Gaussianity measures readily by homodyne detection, which would otherwise require a full quantum-state tomography.

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Jiyong Park, Jaehak Lee, Kyunghyun Baek, Hyunchul Nha. 2021-09-29. Quantifying non-Gaussianity of a quantum state by the negative entropy of quadrature distributions. https://doi.org/10.1103/physreva.104.032415

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