Time-domain interferometry (TDI) is a method to probe space-time correlations among particles in condensed matter systems. Applying TDI to quantum systems raises the general question of whether two-time correlations can be reliably measured without an adverse impact of the measurement backaction on the dynamics of the system. Here, we show that a recently developed quantum version of TDI (QTDI) indeed can access the full quantum-mechanical two-time correlations without backaction. We further generalize QTDI to weak classical continuous-mode coherent input states, alleviating the need for single-photon input fields. Finally, we interpret our results by splitting the space-time correlations into two parts. While the first one is associated with projective measurements and thus insensitive to backaction, we identify the second contribution as arising from the coherence properties of the state of the probed target system, such that it is perturbed or even destroyed by measurements on the system.

中文翻译：

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通过量子时域干涉仪进行无反向作用的量子相关性测量

时域干涉法（TDI）是一种探测凝聚态系统中粒子之间时空相关性的方法。将TDI应用于量子系统提出了一个普遍的问题，即是否可以可靠地测量两次相关性，而不会对测量动力学产生不利影响。在这里，我们表明，最新开发的TDI量子版本（QTDI）确实可以访问完整的量子力学两次关联，而没有反向作用。我们进一步将QTDI推广到弱经典连续模式相干输入状态，从而减轻了对单光子输入场的需求。最后，我们通过将时空相关性分为两部分来解释我们的结果。虽然第一个与投射测量相关联，因此对背向不敏感，