Chip-Scale Integration of Nanophotonic-Atomic Magnetic Sensors

Optical magnetometers based on alkali vapors, such as rubidium, are among the most sensitive technologies for detecting and characterizing magnetic fields. Following the recent effort in miniaturizing atomic-based quantum technologies, the last years were marked by a growing interest in developing integrated quantum nanophotonic circuits for a vast range of applications. Motivated by the attractiveness of such chip-scale integration, we present and experimentally demonstrate an integrated magnetic sensing platform, based on a nanophotonic-chip interfaced to a microfabricated alkali vapor cell. Magnetically induced circular dichroism in rubidium vapor is measured using a planar structure that spatially resolves the handedness of incoming photons depending on their spin. The presented approach paves the way toward further integration of highly sensitive magnetometers, with potential for future applications, such as in high-spatial resolution magnetic vectorial imaging.