Diamond defect sensors offer high sensitivity to magnetic fields due to the action of the field on the quantum spin state of the defect, which is itself a miniature magnet that can be measured with high precision. One of the applications we are working towards with these sensors is medical imaging of the brain – “magnetoencephalography” – and the heart – “magnetocardiography”. Diamond defects offer the possibility of enormous reductions in cost of these procedures compared with existing approaches.
Optical microcavity sensors are spin-off technologies that arise from our efforts to create a light-matter interface for quantum networks. The exquisite sensitivity of such devices can be employed to probe chemical or biological entities in minute quantities of gas or liquid and can be tuned to the absorption/emission frequencies of specific molecules, or nanoscale pathogens. The device offers potential for wide ranging applications in security, healthcare and environmental science, for example point of care diagnostics of early stage viral infection or cancer. So far we have demonstrated some basic functionality of the sensor with selected passive targets, and are investigating both the limits of their sensitivity and the most promising routes towards commercialisation for specific applications.