The goal of this project is to explore an approach for detection of magnetic field, both magnitude and directionality, with less than 1 femto-Tesla resolution and better than 10 microns location error in a 10 square centimeter form-factor. The proposed approach is based on implementation of a densely packed array of glass micro-scale cells. Each cell is a hundred micron in diameter and is filled with isotopes of rubidium and buffer gasses. Cells are equally spaced on the same substrate, a hundred micron apart, and each cell acts as a highly precise all-optical atomic magnetometer. Intellectual Merit: This project will investigate the precession of nuclear spins as the measure of magnetic field magnitude and spatial distribution of magnetometers as a measure of magnetic field gradient. Contrary to SQUIDs, the proposed atomic magnetic gradiometer will not require cryogenic cooling and will not have any moving mechanical parts. A high-performance magnetometry can potentially be achieved by measuring the apparent change of the precession frequency of nuclear spins in response to a weak magnetic field. Broader Impact: Highly sensitive, small size, and easy to use magnetometers can have transformative effects in various areas including biology and biomedical engineering, geology and mineral/oil exploration, as well as surveillance and defense (through wall/underground imaging and target tracking). Small size and convenience offered by the proposed microscale devices can lead to significant advances in brain mapping and enable development of advanced portable brain monitoring devices. The accessibility of such technology for personal use in the form factor of hand-held devices will revolutionize, for example, personal health-care, on-demand diagnostic, and self-monitoring of chronic deceases. The most noticeable contribution will be in the area of biomagnetism, that is, the detection of the weak magnetic fields produced by the human brain, heart, and other organs. This research will advance scientific knowledge in the areas of innovative sensing concepts, signal processing, and system-level implementation. This highly multidisciplinary project will also provide unique educational experience for undergraduate and graduate (including underrepresented) students through team collaborations.
