Limitations of Gaussian measurements in quantum imaging

• URL: http://arxiv.org/abs/2503.06363v2
• Date: Wed, 13 Aug 2025 22:47:49 GMT
• Title: Limitations of Gaussian measurements in quantum imaging
• Abstract summary: We show that non-Gaussian measurements can outperform any Gaussian measurement in the scaling of the estimation variance with $epsilon$ (or $L$)
• Score: 0.9783507779727566
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Imaging thermal sources naturally yields Gaussian states at the receiver, raising the question of whether Gaussian measurements can perform optimally in quantum imaging. In this work, we establish no-go theorems on the performance of Gaussian measurements for imaging thermal sources in the limit of mean photon number per temporal mode $\epsilon \to 0$ or source size $L \to 0$. We show that non-Gaussian measurements can outperform any Gaussian measurement in the scaling of the estimation variance with $\epsilon$ (or $L$). We also present several examples to illustrate the no-go results.

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