Atomic optical antennas enabled by group IV color centers in diamond

An atom-like system could in principle have lossless optical transitions and generate giant electric field intensities at nanoscale distances. Under resonant excitation, these systems can function as efficient optical antennas; however, most of them suffer from interactions with their solid-state surroundings, limiting the antenna efficiency. Here, we demonstrate that germanium vacancy centers (GeVs) in diamond can operate as a high-precision and efficient optical antenna, with million-fold optical intensity enhancement measured in the near field. We also utilize these GeV antennas to detect and manipulate the charge states of nearby carbon vacancies and generate measurable fluorescence from individual vacancies through Forster resonance energy transfer. Our study reveals the capacity of atomic antennas for efficient optical energy concentration in solids, with broad applications in spectroscopy, sensing, and quantum science.