Enhancing photon collection from single shallow nitrogen-vacancy centers in diamond nanopillars for quantum heterodyne measurements

Abstract The developments in quantum sensing protocols and nano-photonic waveguides are merged to improve the performance of single nitrogen-vancancy (NV) centers in nuclear magnetic resonance (NMR) sensing. Nanopillars are designed with NV centers placed approximately 5 nm below the top facet and fabricated through a simple procedure, suitable for mass production. Fluorescence intensities from these nanopillars are 3.5 times greater than that of single shallow NV centers embedded in unstructured flat diamond. Quantum heterodyne measurements of an alternating magnetic field are performed with these nanopillars and evidence of improved peak clarity in the frequency spectrum is shown.