Experimental validation of photonic boson sampling

A boson sampling device is a specialized quantum computer that solves a problem that is strongly believed to be computationally hard for classical computers(1). Recently, a number of small-scale implementations have been reported(2-5), all based on multiphoton interference in multimode interferometers. Akin to several quantum simulation and computation tasks, an open problem in the hard-to-simulate regime is to what extent the correctness of the boson sampling outcomes can be certified(6,7). Here, we report new boson sampling experiments on larger photonic chips and analyse the data using a recently proposed scalable statistical test(8). We show that the test successfully validates small experimental data samples against the hypothesis that they are uniformly distributed. In addition, we show how to discriminate data arising from either indistinguishable or distinguishable photons. Our results pave the way towards larger boson sampling experiments whose functioning, despite being non-trivial to simulate, can be certified against alternative hypotheses.