On-Chip Quantum Interference from a Single Silicon Ring-Resonator Source

Silicon photonics is a promising platform to realize the dense and scalable integration required for quantum computing, communication, and sensing. The authors demonstrate a key building block for this platform, a simple, single source of entangled photons, and use it to observe quantum interference on the same chip. This removes the need for clumsy interfacing of multiple photon sources, as in previous studies, and provides a basis for highly scalable photonic circuits that achieve multi-qubit entanglement.