Quantum compass
{{Short description|Atom-based system to determine relative location}}
The terminology quantum compass often relates to an instrument which measures relative position using the technique of atom interferometry. It includes an ensemble of accelerometers and gyroscope based on quantum technology{{cite magazine|url=https://www.wired.com/story/quantum-physicists-found-a-new-safer-way-to-navigate|title=Quantum Physicists Found a New, Safer Way to Navigate|last1=Chen|first1=Sophia|date=2018|magazine=Wired}} to form an inertial navigation unit.
Description
Work on quantum technology based inertial measurement units (IMUs), the instruments containing the gyroscopes and accelerometers, follows from early demonstrations of matter-wave based accelerometers and gyrometers.{{cite web|url=https://web.stanford.edu/group/scpnt/jse_website/documents/Precision_Nav_Sensors-Atom_Inteferometry-Kasevich.pdf|title=Precision Navigation Sensors based on Atom Interferometry|last1=Kasevich|first1=Mark|date=2012|website=Stanford Center for Position, Navigation and Time}} The first demonstration of onboard acceleration measurement was made on an Airbus A300 in 2011.{{cite news |last1=Dillow |first1=Clay |title=For the First Time, Researchers Use an Atom Interferometer to Measure Aircraft Acceleration |url=https://www.popsci.com/technology/article/2011-09/first-time-researchers-use-atom-interferometer-measure-aircraft-acceleration |access-date=September 29, 2011 |publisher=Popular Science}}
A quantum compass contains clouds of atoms frozen using lasers. By measuring the movement of these frozen particles over precise periods of time the motion of the device can be calculated. The device would then provide accurate position in circumstances where satellites are not available for satellite navigation, e.g. a fully submerged submarine.
Various defence agencies worldwide, such as the US DARPA{{Cite journal|last=Kramer|first=David|date=2014-09-30|title=DARPA looks beyond GPS for positioning, navigating, and timing|journal=Physics Today|volume=67|issue=10|pages=23–26|doi=10.1063/PT.3.2543|issn=0031-9228|bibcode=2014PhT....67j..23K|doi-access=free}} and the United Kingdom Ministry of Defence{{cite news |title=MoD creates 'coldest object in the universe' to trump GPS |date=18 May 2014 |work=The Daily Telegraph |url=https://www.telegraph.co.uk/technology/news/10833087/MoD-creates-coldest-object-in-the-universe-to-trump-GPS.html |access-date=18 May 2014}}{{cite news |title=Quantum positioning system steps in when GPS fails |date=14 May 2014 |work=New Scientist |url=https://www.newscientist.com/article/mg22229694.000-quantum-positioning-system-steps-in-when-gps-fails.html#.U3ijjYFdUud |access-date=18 May 2014}} have pushed the development of prototypes for future uses in submarines and aircraft.
In 2024, researchers from the Centre for Cold Matter of Imperial College, London, tested an experimental quantum compass on an underground train on London's District line.{{cite news |last1=McKie |first1=Robin |title='It's the perfect place': London Underground hosts tests for 'quantum compass' that could replace GPS |url=https://www.theguardian.com/science/article/2024/jun/15/london-underground-quantum-compass-gps-subatomic-instrument-locations |work=The Guardian |date=15 June 2024 |location=London}} During the same year, scientists at the Sandia National Laboratories announced they were able to perform spatial quantum sensing using silicon photonic microchip components, a significant advancement towards the development of compact, portable and inexpensive quantum compass devices.{{cite news |title=Revolutionary Quantum Compass Could Soon Make GPS-Free Navigation a Reality |url=https://scitechdaily.com/revolutionary-quantum-compass-could-soon-make-gps-free-navigation-a-reality/ |access-date=6 November 2024 |publisher=SciTechDaily |date=18 August 2024}}
See also
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