Quantum photonics with layered 2D materials

Solid-state quantum devices use quantum entanglement for various quantum technologies, such as quantum computation, encryption, communication and sensing. Solid-state platforms for quantum photonics include single molecules, individual defects in crystals and semiconductor quantum dots, which have enabled coherent quantum control and readout of single spins (stationary quantum bits) and generation of indistinguishable single photons (flying quantum bits) and their entanglement. In the past 6 years, new opportunities have arisen with the emergence of 2D layered van der Waals materials. These materials offer a highly attractive quantum photonic platform that provides maximum versatility, ultrahigh light–matter interaction efficiency and novel opportunities to engineer quantum states. In this Review, we discuss the recent progress in the field of 2D layered materials towards coherent quantum photonic devices. We focus on the current state of the art and summarize the fundamental properties and current challenges. Finally, we provide an outlook for future prospects in this rapidly advancing field.