  Integrated quantum photonics has recently emerged as a powerful platform for
generating, manipulating, and detecting entangled photons. Multipartite
entangled states lie at the heart of the quantum physics and are the key
enabling resources for scalable quantum information processing. Dicke state is
an important class of genuinely entangled state, which has been systematically
studied in the light-matter interactions, quantum state engineering and quantum
metrology. Here, by using a silicon photonic chip, we report the generation and
collectively coherent control of the entire family of four-photon Dicke states,
i.e. with arbitrary excitations. We generate four entangled photons from two
microresonators and coherently control them in a linear-optic quantum circuit,
in which the nonlinear and linear processing are achieved in a chip-scale
device. The generated photons are in telecom band, which lays the groundwork
for large-scale photonic quantum technologies for multiparty networking and
metrology.
