Progress Towards an Efficient Quantum Network with Neutral Atoms*

Development of a quantum network that interconnects multiple quantum processors or sensors is an outstanding challenge in quantum information science. This capability will open the door to remote entanglement of distant quantum processors and distributed quantum computing. To make this possible, it is crucial to develop a stable and versatile platform which can serve as a building block of a quantum network.

In this work, we introduce a compact, plug-and-play platform -often referred to as a networking “node” -where quantum information can be stored, processed, and distributed. The platform is composed of mm-sized pre-aligned optics (including 4 of MOT beam tubes, dipole trap, GRIN tubes for excitation and optical pumping, etc.) glued on-chip, which has fiber interfaces. Additionally, a parabolic mirror with a numerical aperture of 0.61 is integrated on-chip, serving a dual purpose for atom trapping and photon collection. By design, the system functions as an efficient platform for quantum information processing while maintaining robustness against environmental drift. Currently, two functional nodes based on parabolic mirrors have been put into operation and construction of the third node based on a cavity is underway. 

Utilizing this novel platform, we report our progress towards atom-photon entanglement, wherein a stationary qubit (Rb87 atom) and a flying qubit (photon) share quantum information.