Dipole localization using an integrated radio-frequency atomic magnetometer
Phys. Rev. Applied 25, 034047 – Published 13 March, 2026
DOI: https://doi.org/10.1103/n5bz-416x
Abstract
Optically pumped atomic magnetometers have previously been used in arrays to reject interference from distant sources and enable the sensitive detection of local sources of radio-frequency (rf) signals, which is useful, for instance, in the detection of low-field NMR signals in an unshielded environment. Here, we demonstrate a complementary scheme in which four magnetometer measurements are used to locate a nearby rf source in three dimensions. The methodology relies on the measurement of an rf vector at two different positions and modeling the source as a magnetic dipole of known orientation. In contrast to coil detection, magnetometers have the advantage of measuring signals in a two-dimensional plane, and they do not inductively couple to their environment or each other, making them a strong candidate for localization of hidden rf sources. For this demonstration, we use only a single rf magnetometer to make four measurements of a synchronous and oriented dipole source, but it is expected that this could be replaced by four magnetometers working simultaneously. In addition, this work is greatly aided by the introduction of a fully integrated magnetometer, in which all optics, including lasers, are safely enclosed in a compact head with flexible wired connections. The portable and safe nature of the sensor make it quite valuable for work in the field.
