Coupling Diamond Color Centers to Open Fiber-based Microcavities

Quantum networks [1] are promising for applications such as secure communication and distributed quantum computing. Diamond color center qubits like the nitrogen-vacancy center and the group IV-vacancy centers are excellent node candidates, but they have limited collectable coherent photon emission. Integration into a tunable, open microcavity can boost collection via the Purcell effect [2]. However, the sensitivity of such cavities to vibrations from the environment has so far been a challenge for developing the system further into a quantum network node, capable of entanglement generation. Here we present a new low temperature setup, which provides a low vibration level while maintaining flexibility over the cavity and fiber control. We will report on our most recent results on coupling color centers to the cavity. Such a system may speed up entanglement rates in present day networks by at least a factor of 100, a critical step towards large scale diamond-based quantum networks.

[1] M. Ruf et al., J. Appl. Phys. 130, 070901 (2021)

[2] E. Janitz et al., Optica 7, 1232-1252 (2020)