GPS systems as we have written about were developed for military purposes before the tragedy of Korean Airlines 007 caused the United States to offer them for free to all. But GPS systems require satellite signals around the clock to operate making them unusable in tunnels, underground and even under the sea. For this reason a quantum compass system is being developed by researchers from Imperial College London.
In the laboratory, rubidium atoms are placed in a vacuum chamber and then cooled to a temperature of −273.15C. At this temperature atoms exhibit quantum characteristics with the waves produced can be precisely detected using an accelerometer. If the original location of the atom is known, every change in the location of the atom can be tracked allowing its position in the real world to be known at all times.
The quantum compass, which has been in development since 2018, is being tested on the London Underground because it has tracks that run underground and is a more accurate real-world testing platform. It is still not able to function accurately, is large in size and requires a complex laser system to operate. So at this point for it to be used on a smartphone in the near future is still impossible.
But researchers at Imperial College see it could potentially replace the system of sensors and cables used by the London Underground to track the more than 500 cars that operate each day within just a few years.