Photonic-reconfigurable entanglement distribution network based on silicon quantum photonics
Dongning Liu, Jingyuan Liu, Xiaosong Ren, Xue Feng, Fang Liu, Kaiyu Cui, Yidong Huang, Wei Zhang
Abstract
The entanglement distribution network connects remote users by sharing entanglement resources, which is essential for realizing quantum internet. We propose a photonic-reconfigurable entanglement distribution network (PR-EDN) based on a silicon quantum photonic chip. The entanglement resources are generated by a quantum light source array based on spontaneous four-wave mixing in silicon waveguides and distributed to different users through time-reversed Hong–Ou–Mandel interference by on-chip Mach–Zehnder interferometers with thermo-optic phase shifters (TOPSs). A chip sample is designed and fabricated, supporting a PR-EDN with 3 subnets and 24 users. The network topology of the PR-EDN could be reconfigured in three network states by controlling the quantum interference through the TOPSs, which is demonstrated experimentally. Furthermore, a reconfigurable entanglement-based quantum key distribution network is realized as an application of the PR-EDN. The reconfigurable network topology makes the PR-EDN suitable for future quantum networks requiring complicated network control and management. Moreover, it is also shown that silicon quantum photonic chips have great potential for large-scale PR-EDN, thanks to their capacities for generating and manipulating plenty of entanglement resources.