Dr Dominic Hunter - University of Strathclyde

Dr Hunter’s research aims to develop advanced quantum magnetometers, specifically optically pumped magnetometers (OPMs), demonstrating high precision, accuracy, reliability, and scalability. These devices offer an exceptional platform for magnetic imaging, which has significant applications across sectors such as security, geophysics, and navigation. For instance, detecting solar weather events can help protect critical national infrastructure, such as the power grid, thereby preventing severe economic disruptions in the UK. Additionally, OPMs can be employed for concealed object detection at airports, seaports, and other high-security locations, thereby enhancing national security. OPM prototype development will prioritise key performance metrics, including sensitivity and stability. To achieve the highest levels of precision, corresponding to a part-per-billion of the Earth’s magnetic field, innovative techniques in magnetometry and vapour cell fabrication will be implemented. A central focus of this work is the stability of OPMs, which is crucial for avoiding drifts and ensuring the clear detection of magnetic signals of interest. Most current commercial systems, such as the classical fluxgate magnetometers, often suffer from drifts and require frequent recalibration when operating in the Earth’s ambient magnetic field conditions. This research proposes a self-calibrating method based on free-induction-decay (FID) to address these challenges. The FID technique involves two sequential stages: first, optical pumping orientates the atomic spins coherently along the beam direction using intense resonant laser light; second, detection occurs when the light is switched off, allowing the atomic spins to rotate freely in the presence of external magnetic fields – a phenomenon known as Larmor precession. This rotation is detected using weak off-resonant light, ensuring high accuracy and minimising systematic drifts.