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arXiv · 2412.17223

Temporally localized quantum operations on continuous-wave thermal light

Yunkai Wang·Yujie Zhang·Virginia O. Lorenz
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Abstract

Previous work showed that thermal light with a blackbody spectrum cannot be decomposed into a mixture of independent localized pulses. However, we find that in the weak-source limit and under the assumption of a flat spectrum, the first non-vacuum term in the state expansion does form a mixture of such pulses. This decomposition is essential for quantum-enhanced astronomical interferometry, which typically operates on localized pulses even though stellar light is inherently continuous-wave. We present a quantum derivation of the van Cittert-Zernike theorem that incorporates finite bandwidth, thereby justifying the operations on localized pulses while processing continuous-wave thermal light. For general spectra in the weak-source limit, we establish a criterion under which correlations between pulses can be safely neglected. When this criterion is not met, we provide a corrected strategy that accurately accounts for both the spectral profile and the detector-defined pulse shape.

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Yunkai Wang, Yujie Zhang, Virginia O. Lorenz. 2024-12-23. Temporally localized quantum operations on continuous-wave thermal light. https://arxiv.org/abs/2412.17223

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