STAGE Optical Hybrid Quantum Information

In analogy to what has happened for classical signals with the digital and analog paradigms, quantum information has developed along two traditionally separated lines, known as the discrete- and the continuous-variable approaches. In the optical approach, the wave-particle duality of light has naturally led to this distinction. The discrete-variable approach involves for instance single photons and the states live in a finite-dimensional space spanned, among others, by orthogonal polarizations or the presence and absence of single photons. In the continuous-variable alternative, the encoding is realized in the amplitude or phase of a light field, in an inherently infinite-dimensional space. The typical detection and processing tools are different, based either on photon counting or homodyne detection. A variety of groundbreaking experiments have been realized using one or the other paradigm.