Sensor breakthrough paves way for groundbreaking map of world under Earth surface

 

Quantum technology has been used to find a subterranean object, a long-awaited milestone with far-reaching ramifications for industry, human knowledge, and national security.

Researchers from the UK National Quantum Technology Hub in Sensors and Timing from the University of Birmingham have published their findings in Nature. It's the first time a quantum gravity gradiometer has been used outside of a lab setting.

The quantum gravity gradiometer, which was created for the Ministry of Defence under a contract and as part of the UKRI-funded Gravity Pioneer project, was used to locate a tunnel buried one metre below the earth surface in real-world conditions. It triumphs in an international competition to bring the technology outside.

The sensor detects changes in microgravity using quantum physics concepts, which are based on influencing nature at the sub-molecular level.

The success pave the way for much enhanced mapping of what exists below ground level on a commercial scale.

This will Mean:

• Construction, rail, and road projects will have lower costs and delays as a result of this.
• Improved prediction of natural occurrences such as volcanic eruptions.
• Hidden natural resources and man-made constructions are discovered.
• Understanding archaeological puzzles without hurting excavation.

"This is a 'Edison moment' in sensing that will revolutionise society, human understanding, and economies," said Professor Kai Bongs, Head of Cold Atom Physics at the University of Birmingham and Principal Investigator of the UK Quantum Technology Hub Sensors and Timing.

"With this discovery, we may be able to move away from relying on bad records and luck while exploring, building, and repairing. Furthermore, a subterranean map of what is currently unseen is now a considerable step closer, putting an end to the predicament in which we know more about Antarctica than what lies a few feet beneath our streets."

The capabilities of modern gravity sensors are limited by a range of environmental factors. Vibration is a unique problem because it shortens the measuring time of all gravity sensors used in surveying. If these limitations are solved, surveys can become faster, more comprehensive, and less expensive.

Dr. Michael Holynski, Head of Atom Interferometry at Birmingham and the study's principal author, and his colleagues at Birmingham constructed a gravity gradiometer. To successfully implement quantum technology in the field, their method overcomes vibration and a range of other environmental difficulties.

The successful detection, which was carried out in partnership with civil engineers led by Professor Nicole Metje of the School of Engineering, is the culmination of a long-term development programme that has always been intimately linked to end-users.

Future gravity surveys will be cheaper, more reliable, and delivered 10 times faster as a result of this accomplishment, cutting survey time from a month to a few days. It has the ability to expand the scope of gravity surveying by providing a new perspective on the subterranean.

RSK's Director of Geoscience and Engineering, Professor George Tuckwell, said: "The ability to plan, develop, and manage housing, industry, and infrastructure requires the detection of ground conditions such as mine workings, tunnels, and unstable ground. The enhanced capabilities represented by this new technology has the potential to change how we map the ground and deliver these projects."

Dr. Gareth Brown, Senior Principal Scientist at Dstl and joint Project Technical Authority for Quantum Sensing, said: "Accurate and rapid measurements of variations in microgravity open up new opportunities for national defence and security to detect the otherwise undetectable and navigate more safely in challenging environments. Applications for underwater navigation and illuminating the subterranean will become conceivable as gravity sensing technology advances."

The discovery is the result of a collaboration between the University of Birmingham, RSK, Dstl (the Defence Science and Technology Laboratory, part of the UK Ministry of Defence), and Teledyne e2v, a provider of environmental, engineering, and sustainability solutions. The project is financed by UKRI as part of the UK National Quantum Technologies Programme and is carried out under contract with the Ministry of Defence.

Reference:

• Stray, B., Lamb, A., Kaushik, A. et al. Quantum sensing for gravity cartography. Nature, 2022 DOI: 10.1038/s41586-021-04315-3