Enhanced Readout and Sensitivity of Diamond N-V Centers Coupled to Hyperbolic Metamaterial Photonic Cavities

Nitrogen-vacancy (N-V) centers are diamond lattice defects that may be manipulated and controlled by visible light and microwave irradiation. They are considered a promising solid-state platform for a broad range of quantum technologies, such as magnetic field sensing. A major limitation in realizing such applications is the weak optical signal attained from the NVs, making the readout inefficient and prone to noise. Here, we report the increased brightness and shortened lifetime of N-V centers coupled to hyperbolic metamaterial photonic cavities with optimized dispersion characteristics. As a result, we demonstrate the enhancement of magnetic field sensitivity and measurement SNR. These results introduce a broadly applicable, robust, and technically accessible platform, promising improved performance relevant for a multitude of solid-state defects and their applications.