Estimating Non-Gaussianity of a Quantum State by Measuring Orthogonal Quadratures |
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Authors: | Jiyong Park |
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Affiliation: | School of Basic Sciences, Hanbat National University, Daejeon 34158, Korea; |
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Abstract: | We derive the lower bounds for a non-Gaussianity measure based on quantum relative entropy (QRE). Our approach draws on the observation that the QRE-based non-Gaussianity measure of a single-mode quantum state is lower bounded by a function of the negentropies for quadrature distributions with maximum and minimum variances. We demonstrate that the lower bound can outperform the previously proposed bound by the negentropy of a quadrature distribution. Furthermore, we extend our method to establish lower bounds for the QRE-based non-Gaussianity measure of a multimode quantum state that can be measured by homodyne detection, with or without leveraging a Gaussian unitary operation. Finally, we explore how our lower bound finds application in non-Gaussian entanglement detection. |
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Keywords: | non-Gaussianity relative entropy homodyne detection |
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