Monolithic integration, which refers to the incorporation of all device functionalities within a single material, shows significant potential for creating scalable solid-state quantum devices. This study demonstrated the coherent control of nitrogen-vacancy (NV) spins using an electronic circuit monolithically integrated within diamond: a patterned, conductive boron-doped diamond (BDD) microwave waveguide. First, we validated the high-frequency performance of the circuit by characterizing its impedance up to the microwave range, confirming its capability for efficient microwave transmission. Then, using this monolithically integrated BDD--NV hybrid system, we performed optically detected magnetic resonance and observed noticeable Rabi oscillations driven by the metallic BDD circuit. Importantly, we verified that the BDD antenna has a minimal detrimental impact on the NV spins; microwave-induced heating is negligible under both pulsed and continuous driving, and the spin relaxation time (T1) remains unperturbed. This approach paves the way for a new class of compact, robust, and versatile quantum platforms suitable for sensing and information processing in various environments.
@article{arxiv.2412.15586,
title = {Coherent control of solid-state defect spins via patterned boron-doped diamond circuit},
author = {Masahiro Ohkuma and Eikichi Kimura and Eunsang Lee and Ryo Matsumoto and Shumpei Ohyama and Saki Tsuchiya and Harim Lim and Yong Soo Lee and Yoshihiko Takano and Junghyun Lee and Keigo Arai},
journal= {arXiv preprint arXiv:2412.15586},
year = {2025}
}