Following recent progress in the experimental application of electro-optic sampling to the detection of the quantum fluctuations of the electromagnetic-field ground state and ultrabroadband squeezed states on a subcycle scale, we propose an approach to elevate broadband electro-optic sampling from a spectroscopic method to a full quantum tomography scheme, able to reconstruct a free-space quantum state directly in the time domain. By combining two recently developed methods to theoretically describe quantum electro-optic sampling, we analytically relate the photon-count probability distribution of the electro-optic signal to a transformed phase-space quasiprobability distribution of the sampled quantum state as a function of the time delay between the sampled midinfrared pulsed state and an ultrabroadband near-infrared probe pulse. We catalog and analyze sources of noise and show that in quantum electro-optic sampling with an ultrabroadband probe pulse one can expect to observe thermalization due to entanglement breaking. Mitigation of the thermalization noise enables a tomographic reconstruction of broadband quantum states while granting access to its dynamics on a subcycle scale. Published by the American Physical Society 2024

中文翻译：

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亚周期尺度上的光学时域量子态断层扫描


随着电光采样在子周期尺度上电磁场基态和超宽带压缩态的量子涨落检测的实验应用的最新进展，我们提出了一种方法，将宽带电光采样从光谱方法提升为全量子层析成像方案，能够直接在时域中重建自由空间量子态。通过结合两种最近开发的方法从理论上描述量子电光采样，我们分析地将电光信号的光子计数概率分布与采样量子态的变换相空间准概率分布联系起来，作为采样的中红外脉冲态和超宽带近红外探测脉冲之间的时间延迟的函数。我们对噪声源进行编目和分析，并表明在使用超宽带探测脉冲的量子电光采样中，可以预期观察到由于纠缠断裂而导致的热化。减轻热化噪声可实现宽带量子态的断层重建，同时允许在子周期尺度上访问其动力学。 美国物理学会 2024 年出版