Integration of nanometer thin diamond membranes in plasmonic cavities: a roadmap to ultrafast emissions

Solid-state emitters such as defect centers in diamond are promising candidates for quantum information and sensing applications. Despite ongoing efforts to achieve bright and fast sources, low photon extraction efficiencies and slow spontaneous emission rates limit the practicality of devices. Here, we discuss a novel ultrathin diamond membrane fabrication technique to realize sub-diffraction limited plasmonic cavities coupled to silicon vacancy (SiV) centers in diamond [1]. Au nanodisks are prepared by electron beam lithography and arrays are transferred onto diamond membranes using a PDMS stamping procedure. Plasmonic integration of SiV centers results in over 135-fold spontaneous emission rate and 19-fold brightness enhancement. Our investigations into implantation depth, diamond thickness and cavity parameters provide guidelines for creating bright and ultrafast plasmonic photon sources for next-generation quantum applications. Reference 1. Boyce, A. M.; Li, H.; Wilson, N. C.; Acil, D.; Shams-Ansari, A.; Chakravarthi, S.; Pederson, C.; Shen, Q.; Yama, N.; Fu, K. C.; Loncar, M.; Mikkelsen, M. H. Nano Letters 24 (12), 3575-3580 (2024).