Diamonds are GPS’s best friend 

While much of the attention of quantum technologies is around quantum computing, the most immediate and impactful application of the technology will be in the realm of quantum sensing. And one of the most promising applications of quantum sensing is for navigation, without requiring GPS satellite systems. 

The application uses a quantum phenomenon called Nitrogen Vacancy Diamond Center defects.  These defects occur in a diamond crystal lattice when a nitrogen atom (red) replaces a carbon atom (green) resulting in a vacancy (clear labeled with V) in the diamond lattice structure. Through laser interrogation of the site, an extremely precise measurement can be made of external magnetic field. 

While there are many applications for magnetometry, one use is navigation. Compasses use the Earth’s magnetic field to point north. However, the local variations in the magnetic vector can be used, along with a map of the earth’s magnetic variations, to update one’s location and orientation on earth.   

The required map uses variations (vector direction and strength) of the local magnetic field which is affected by Earth’s underground mineral deposits in measurable ways. Navigation is a consequence of using an inertial navigation system (which can also use quantum sensing) that is corrected by comparison against a prestored map of the local magnetic field as a function of location.  

While NV Center Diamond technology has been known and understood for a decade, there are challenges to productizing the technology. A magnetometer using the technology can be made small, lightweight, perhaps even residing on a chip.  Magnetic interference from electrical circuits and nearby magnetic fields need to be eliminated. But the idea is that when productized, drones, satellites, and certain ground and undersea vehicles might be able to navigate without access to space-based GPS This is one of the application areas of quantum sensing being explored in the DARPA “Robust Quantum Sensors” project. 

These developments are truly international among allies and friends, with Germany and the EU leading in engineering maturity, the United States leading in defense-driven applications, and Australia as a center of excellence for deployable diamond quantum systems. As an example of the progress being made, in mid-2025, the Fraunhofer Institute for Applied Solid State Physics announced a new level of miniaturization in a magnetometer with “easy calibration, high sensitivity…and a wide range of applications in biomedicine, materials testing, navigation, and geology.”  Many other companies, including small businesses and major defense companies, are working on developing the technology to deploy GPS-free navigational devices. 

Some technologies happen quickly and rapidly lead to capabilities.  But often, as with NV Center Diamond technology, the science develops through decades of discovery and gradual technology maturation. In the end, what once looked like magic, is tech that just “happened”.