The identification of phenomena able to pinpoint quantum interference is attracting large interest. Indeed, a generalization of the Hong–Ou–Mandel effect valid for any number of photons and optical modes would represent an important leap ahead both from a fundamental perspective and for practical applications, such as certification of photonic quantum devices, whose computational speedup is expected to depend critically on multi-particle interference. Quantum distinctive features have been predicted for many particles injected into multimode interferometers implementing the Fourier transform over the optical modes. Here we develop a scalable approach for the implementation of the fast Fourier transform algorithm using three-dimensional photonic integrated interferometers, fabricated via femtosecond laser writing technique. We observe the suppression law for a large number of output states with four- and eight-mode optical circuits: the experimental results demonstrate genuine quantum interference between the injected photons, thus offering a powerful tool for diagnostic of photonic platforms.
- quantum information
- quantum optics
- boson sampling
Crespi, A., Osellame, R., Innocenti, L., Bentivegna, M., Ramponi, R., Flamini, F., Spagnolo, N., Viggianiello, N., Mataloni, P., & Sciarrino, F. (2016). Suppression law of quantum states in a 3D photonic fast Fourier transform chip. Nature Communications, 7(10469), . https://doi.org/10.1038/ncomms10469