Quantum sensing and the environment

Energy Infrastructure and Efficiency

The past few years have made us more aware that scientists and engineers must develop technologies to manage and mitigate climate change. Furthermore, geopolitics in Europe have also brought into focus the sourcing of energy as a critical consideration for every country - whether it has a developing or developed economy. Quantum technologies could offer greater levels of security and safety in this regard. This would entail monitoring gas and oil flow through pipelines and boreholes. High-performance thermometers are important for measuring the performance of power systems, pipeline integrity, and explosion risks in oil processing facilities. NV-based thermometers can function under harsh conditions such as at temperatures above 250 ℃, high pressure, and corrosivity. The diamond is highly sensitive to strain on the lattice which is induced by temperature and therefore the optically detected magnetic resonance shifts ~ 74 kHz/℃, making the NV-center a highly sensitive thermometer. This would be important for the development of a more efficient energy infrastructure. NV-centers are also sensitive to pH as well as ions using a technique called relaxometry. The presence of ions and acidic or basic pH levels could indicate corrosion and degradation of energy infrastructure. Furthermore, NV-centers can image magnetic fields from current flow such as electricity generation.

Unlocking environmental stories within rocks

An application of the quantum diamond microscope lies in unlocking information within rocks by imaging magnetic particle enrichment in geological mineral deposits with annual resolution. This is one way for scientists to compare local environments today to that of the past. Detection of magnetism such as from iron in sedimentary rocks is sensitive to properties such as grain size and oxidation state. Magnetization intensity such as from the prevalence of ferromagnetic detrital particles in sedimentary rocks is associated with oxygen isotope variations. It also gives records of precipitation, runoff, and soil pH. Therefore magnetic imaging techniques are suited for quantitatively analyzing climatic and chemical conditions during the deposition of the sediment. With annual time resolution effects as the El Ninõ Southern Oscillation can be observed. Experimentally, Roger Fu’s group at Harvard mapped the magnetic fields within Brazilian speleothem, which are mineral deposit rock formations in caves. The images were then processed with procedures such as background subtraction and stitching. They obtained a time series of magnetic field strength as a proxy for magnetization with an age model. Subregions were analyzed in this way to get magnetization in specific sub-areas. Their time series extended over 174 years, and suggests that a slowdown in deposition may also lead to high Fe content. This was compatible with oxygen isotopic data and indicates that detrital enrichment can serve as a tool to understand the surrounding environment at the time of rock formation.