A quantum technology breakthrough has led to the discovery of a hidden object belowground. This milestone will have profound implications for industry, human know-how, and national security.
Researchers from the UK National Quantum Technology Hub in Sensors and Timing at the University of Birmingham have published their achievements in Nature. This is the first quantum gravity gradiometer used outside of laboratory conditions.
The Quantum Gravity Gradiometer was built under contract by the Ministry of Defence. It was part of the UKRI-funded Gravity Pioneer project. It was used to locate a tunnel buried outdoors, one meter below the ground, in real-world conditions. It is the winner of an international race to bring the technology outside.
The sensor detects variations in microgravity by using quantum physics principles, which are based on manipulating Nature at sub-molecular levels.
This success has opened up a commercial route to greatly improved mapping below ground.
This will be:
- Construction, rail and road projects are less expensive and have fewer delays.
- Improved prediction for natural phenomena like volcanic eruptions.
- Discover hidden natural resources and built structures
- Without damaging excavation, it is possible to understand archaeological mysteries.
Professor Kai Bongs is the Head of Cold Atom Physics at Birmingham and the Principal Investigator of UK Quantum Technology Hub Sensors and Timing. He said that this was an “Edison moment” in sensing which will transform society, understanding and economies.
This breakthrough has the potential to end our reliance on luck and poor records as we explore, build, and repair. A map underground of what is invisible is also a step closer. This will end a situation where we know less about Antarctica than the information that lies just a few feet below our street.
The environmental factors that affect gravity sensors today can limit their performance. Vibration is a problem that limits all gravity sensors used for survey purposes. These limitations can be overcome to make surveys more efficient, comprehensive, and less expensive.
The gravity gradiometer is the sensor that Dr Michael Holynski (Head of Atom Interferometry at Birmingham) and his team at Birmingham developed. The system can withstand vibrations and other environmental challenges when applying quantum technology.
This successful detection was made possible by the School of Engineering’s civil engineers, Professor Nicole Metje. It is the culmination of an extensive development program closely connected to end-users since its inception.
How does the quantum gravity sensor work
Quantum gravity sensors measure subtle changes in gravitational fields’ pulling power when atoms are dropped from a cloud. The stronger the pull measurement is, the larger the object and the greater the distance between it and its surrounding objects. However, quantum theory has been difficult to commercialize because of vibrations, instrument tilt and disruption by magnetic and thermal fields. This breakthrough Birmingham quantum sensor is the first to address these real-world problems and conduct a high spatial resolution survey. Gravity mapping with high spatial resolution will be possible by removing vibration noise.
The breakthrough will make future gravity surveys more affordable, reliable, and faster and deliver results 10 times faster. This will reduce the survey time from several months to just a few days. This breakthrough could open up new opportunities for gravity surveys and provide a new perspective on the underground.
RSK’s Director of Geoscience and Engineering, Professor George Tuckwell, said that “detection of ground conditions, such as mine works, tunnels and unstable ground, is fundamental to our ability design, construct, maintain housing, industry and infrastructure.” This new technology could revolutionize how we map to ground and deliver these projects.
Dr Gareth Brown is a joint Project Technical Authority for Quantum Sensing and Senior Scientist at Dstl. He stated: “For national Defence and Security, accurate and rapid measurements in microgravity open new opportunities to detect what was otherwise undetectable and navigate safely in more challenging environments. As gravity sensing technology matures, applications for underwater navigation and uncovering the underground will be possible.
