Quantum Sensing and Metrology

Quantum sensing is the most exciting quantum technology and it has the most potential to change our lives in the next decade and beyond. Quantum sensors will offer new capabilities with benefits for medicine, defense, intelligence, extractive industries and many others. Quantum sensing is a precursor technology to quantum computing and communications. Quantum sensors use quantum properties and effects to measure or sense physical things. This chapter explores quantum sensing as a topic in its own right, because the capabilities of quantum sensing are surprising and offer new forms of knowledge discovery and at new levels of analysis. Furthermore quantum sensors are here today---indeed, they have been in use for more than fifty years.