An object concealed underground has been traced utilizing quantum technology — a long-awaited breakthrough with deep implications for national security, industry and human knowledge.
This achievement has been reported by the University of Birmingham researchers from the UK National Quantum Technology Hub in Sensors and Timing in the journal Nature. It is the first in the realm for a quantum gravity gradiometer outside of laboratory settings.
The quantum gravity gradiometer, which was built under a contract for the Ministry of Defense and in the UKRI-funded Gravity Pioneer project, was used to locate a tunnel buried outdoors in real-world conditions 1 m below the ground surface. It is leading the way in the global race to launch the technology outside.
The sensor functions by identifying variations in microgravity applying the principles of quantum physics, which is based on controlling nature at the sub-molecular level.
The success paves a commercial path to considerably enhanced mapping of what is present below ground level.
This will mean:
- Decreased costs and delays to construction, road and rail projects.
- Better prediction of natural occurrences such as volcanic eruptions.
- Discovery of unknown natural resources and built structures.
- Unraveling archaeological mysteries without destroying excavation.
This is an ‘Edison moment’ in sensing that will transform society, human understanding, and economies. With this breakthrough, we have the potential to end reliance on poor records and luck as we explore, build and repair. In addition, an underground map of what is currently invisible is now a significant step closer, ending a situation where we know more about Antarctica than what lies a few feet below our streets.
Professor Kai Bongs, Head of Cold Atom Physics, University of Birmingham
Professor Kai Bongs is also the Principal Investigator of the UK Quantum Technology Hub Sensors and Timing – University of Birmingham.
Existing gravity sensors are limited by a variety of environmental factors. A specific challenge is vibration, which restricts the time taken for measurement in all gravity sensors used for survey applications. If these limitations can be resolved, surveys can be completed faster in a more comprehensive way at a lower cost.
The sensor, a gravity gradiometer, was built by Dr. Michael Holynski, Head of Atom Interferometry at Birmingham and lead author of the study, and his team at Birmingham. The system surpasses vibration and a range of other environmental challenges so as to effectively apply quantum technology in the real world.
The successful detection, realized in partnership with civil engineers guided by Professor Nicole Metje of the School of Engineering, is the result of a long-standing development program that has been closely associated with end-users from its inception.
This innovation will enable future gravity surveys to be more reliable, economical and ready 10 times faster, reducing the time required for surveys from a month to a few days. It has the potential to lead to a variety of new applications for gravity survey, offering a new lens into the underground.
Professor George Tuckwell, Director for Geoscience and Engineering at RSK, stated: “Detection of ground conditions such as mine workings, tunnels, and unstable ground is fundamental to our ability to design, construct and maintain housing, industry, and infrastructure. The improved capability that this new technology represents could transform how we map the ground and deliver these projects”
For national Defence and Security, accurate and rapid measurements of variations in microgravity open up new opportunities to detect the otherwise undetectable and navigate more safely in challenging environments. As gravity sensing technology matures, applications for underwater navigation and revealing the subterranean will become possible.
Dr. Gareth Brown, Joint Project Technical Authority for Quantum Sensing and Senior Principal Scientist, Defense Science and Technology Laboratory
The innovation is a partnership between the University of Birmingham, environmental, engineering and sustainability solutions provider RSK, Dstl (the Defense Science and Technology Laboratory, part of the UK Ministry of Defense), and technology company Teledyne e2v.
The study received funding from the UK Research and Innovation (UKRI) as part of the UK National Quantum Technologies Program and under contract from the Ministry of Defense.
Stray, B., et al. (2022) Quantum sensing for gravity cartography. Nature. doi.org/10.1038/s41586-021-04315-3.