Question: how do you create a quantum sensor to detect an object under ground just using the strength of gravity

Bruce Saleeb-Mousa answered on 13 Mar 2020:

Good question! Quantum sensors rely on the properties of atoms to detect very small changes in the environment which can include detecting the strength of gravity.

To do this, we start off by taking a gas of a special type of atoms called alkali atoms. To make these atoms sensitive to gravity we have to first trap them into a small cloud and then cool them down to -273 degrees C.

To do this we use laser beams, magnetic fields and a vacuum chamber. The vacuum chamber helps to get rid of any other gases we don’t want to interfere with our experiment and the laser beams and magnetic fields are used to trap the atoms into a cloud inside the chamber.

To measure gravity, we release the atoms from the trap by turning off the laser beams and let them fall under gravity. The strength of gravity changes the properties of the atoms which we can then ‘read’ using other laser beams as they fall. We repeat this over and over to get a measurement of the local gravity.

If we do this in different areas, we can create a map of the strength of gravity which allows us to see if there are any objects underground since this would change the strength of gravity by a very small amount. The devices I make will be used to control the laser beams which I mentioned which will help to make these sensors smaller.