2019-110 – Diamond Vector Magnetometer Enhanced by Flux Concentrators

Background Vector magnetometers are instruments that record the ambient magnetic flux density and its three-dimensional direction of a magnetic field. They have applications in geophysical and archaeological surveys, space missions, and position, navigation, and timing (PNT) devices. Such diverse and rugged applications require the instruments to not only be durable, but easy to transport and minimally reliant on any power sources. Traditional magnetometers fail in these respects; oftentimes being expensive, fragile, bulky, low-resolution, or having a high operating power. Sensors based on solid-state spins; however, have been amassing attention due to their unique ability to operate in a wide range of harsh environments and their miniaturizability. Particularly, diamond nitrogen-vacancy (NV) centers present ensembles with spin properties that offer exceptional sensitivity to magnetic fields, temperature, and electric fields in ambient conditions. Despite the popularity, diamond vector magnetometers encounter significant obstacles of their own: the optically detected magnetic resonance (ODMR) spectrum at Earth’s magnetic field, and relatively high operating powers. Recent approaches have attempted to apply a bias field in an effort to separate the ODMR lines, but stabilizing the bias field and reducing operating power in a field-deployable device presents a major challenge. Technology Description Researchers at the University of New Mexico have developed a diamond vector magnetometer enhanced by flux concentrators, capable of operating at earth’s magnetic field without added bias fields. The nitrogen-vacancy (NV) doped micro-diamond can perform magnetometry at the sub-picotesla level, while exhibiting a total operating power below 30 mW. Featuring a dynamic range of ±0.1 mT, the magnetometer will allow the magnetic field vector to be measured with an accuracy of <0.01 degrees in field angle. The proposed magnetometer exhibits two orders-of-magnitude power consumption improvement over traditional magnetometers and currently utilized diamond vector magnetometers. The low-reliance on power, high sensitivity, miniaturizability, and independency of a bias field, provide all the requirements for an efficient, field-deployable device. Andrew Roerick aroerick@innovations.unm.edu 505-277-0608