Entangled two-photon spectroscopy is expected to provide advantages compared with classical protocols. It achieved by coherently controlling the spectral properties of energy-entangled photons. We present here an experimental setup that allows shaping entangled photons high resolution. evaluate its performances detecting sum frequency generation in a non-linear crystal. The efficiency process w...

We characterize entanglement subject to its definition over real and complex, composite quantum systems. In particular, a method is established assess correlations with respect selected number system, illuminating the deeply rooted, yet rarely discussed question of why states are described via complex numbers. With our experiment, we then realize two-photon polarization that entangled notion tw...