The fundamental building block of a quantum internet are quantum nodes, that exhibit coherent localized spins and an efficient spin-photon interface to establish remote entanglement in a network. Using Nitrogen-Vacancy center enriched diamond samples in an open-microcavity setup is a promising platform to realize quantum nodes with unprecedented performance.

State of the art Nitrogen-Vacancy center-based quantum nodes are using bulk diamond samples with solid immersion lenses in a confocal microscopy setup [1]. These systems show very good spin properties, but only a poor spin-photon interface. It was demonstrated that good spin properties of the NV center can be preserved in micrometer-thin samples, which enables their integration into open-microcavities [2]. These cavities in turn boost the spin-photon interface by the Purcell effect and hence allow to overcome current limitations in scaling up a quantum network [3].

This project is designed with 2 possible directions for which 2 positions are available. The focus of each direction of the project can be adjusted to your interests.

1. One project direction offers the opportunity to design, fabricate, characterize and optimize thin diamond samples in a state-of-the-art cleanroom, as well as preliminary characterization of the obtained devices.
2. The other project direction offers the possibility to extensively characterize, integrate and optically investigate the diamond samples in an open-microcavity setup in a quantum optics laser laboratory.

Join the project

If you are interested to join this project, please contact Julius Fischer, Yanik Herrmann or Nina Codreanu.

References

[1] M. Pompili, S. L. N. Hermans, et. al., Realization of a multinode quantum network of remote solid-state qubits, Science 372, 259–264 (2021)

[2] M. Ruf et. al., Optically Coherent Nitrogen-Vacancy Centers in Micrometer-Thin Etched Diamond Membranes, Nano Letters 19, 3987–3992 (2019)

[3] M. Ruf, et. al., Resonant Excitation and Purcell Enhancement of Coherent Nitrogen-Vacancy Centers Coupled to a Fabry-Perot Microcavity, Physical Review Applied 15, 024049 (2021)