Quantum entanglement has emerged as a great resource for studying the interactions between molecules and radiation. We propose a new scheme of stimulated Raman scattering with entangled photons. A quantum ultrafast Raman spectroscopy is developed for condensed-phase molecules, to monitor the exciton populations and coherences. Analytic results are obtained, showing an entanglement-enabled time-frequency scale not attainable by classical light. The Raman signal presents an unprecedented selectivity of molecular correlation functions, as a result of the Hong-Ou-Mandel interference. Our work suggests a new paradigm of using an unconventional interferometer as part of spectroscopy, with the potential to unveil advanced information about complex materials.

量子纠缠已成为研究分子与辐射之间相互作用的重要资源。我们提出了一种利用纠缠光子进行受激拉曼散射的新方案。为凝聚相分子开发了量子超快拉曼光谱，以监测激子数量和相干性。获得的分析结果显示了经典光无法实现的纠缠时频尺度。由于红欧曼德尔干涉，拉曼信号呈现出前所未有的分子相关函数选择性。我们的工作提出了一种使用非常规干涉仪作为光谱学一部分的新范例，有可能揭示有关复杂材料的先进信息。