Quantum Sensing

There are so many quantum technologies emerging in recent decades. However, some of them may be considered to be hyped like quantum simulations, quantum encryption, quantum risk management, etc. While there is one already present and useful, ie. quantum sensing.

The sensors rely on the baffling behaviour of subatomic particles. The spooky action we can just think of them as waves, as waves can be in several places at once. This new cutting-edge technology-quantum sensing will be implementing to develop quantum gravity sensors or gravimeters that will be twice as sensitive and 10 times as fast as current equipment.

In Construction

Gravity Pioneer simplifies how engineers and surveyors plan and execute major construction projects. The current can hardly detect the top of the mine shaft 5 meters or more below the ground, this is a big risk for construction firms. Using rubidium atoms cooled by lasers to just about 0K that are propelled upward in a vacuum and then measured as they fall back under gravity. The sensitivity is very high that a tiny fluctuation in gravity can result from small underground structures. Quantum sensing help speed up survey times, it becomes a commercial model

 

In Volcanoes

A network of 40 tiny gravimeters on Sicily’s Mount Etna, one of the most active volcanoes in the world. Magma chambers fill up below ground their gravity readings will change, thus giving advanced warning of volcanic activity.

• Current instruments:
• Seismometers
• Ground deformation recorders
• Gas monitors
• Infrared camera
• Satellite images

There is a risk on the active volcano to move around, so it has been dangerous to collect data for years. On the contrary, using quantum sensing can prevent researchers present in the risky environment. Besides, micro and nanofabrication techniques to make tiny quantum gravimeters on silicon wafers that are 10 times cheaper than conventional models. It is a mass on a soft spring, which depends on gravity.

3D type of lidar

Measure the distance to an object by illuminating it with pulsed laser light and then measuring the reflected pulses. Quantum sensing allows us to measure the arrival time of single photons with very high accuracy, in trillionths of a second. The light bounces off walls then you can get the 3D image from collecting and analyzing the data. The aim is to develop self-driving car lidar to give them enhanced awareness through fog smoke, and over longer distances. It can detect moving people 100m away and a few meters around a corner.

The magnetic field is often the easiest thing for a quantum system to measure. As we know elementary particles have spin, which provides magnetic dipole moment. The famous effect is where the magnetic field causes one energy level of the quantum system to split into multiple zones, with an energy gap proportional to the applied field. Using quantum sensors can directly measure this splitting and extract the B-field from the result. 

Though, quantum sensors cannot be a useful magnetometer. Since they need to be miniaturized. The structure of the quantum sensors requires a big vacuum chamber and a room full of lasers make it less ideal than solid-state sensors of comparable specification. 

The superconducting quantum interference device has been invented since the 1960s, now it can reach the sensitivities of 1fT\sqrts. The drawback is that they need to sit in a cryogenic environment. 

Health Benefit

MRI is too expensive and complicated to diagnose the patient's problem. The detection of degenerative disease is also set to change thanks to quantum sensing. SQUIDs can be applied to magnetic imaging of natural brain activity. 

The processing speed of the spinal cord to the brain changes due to the presence of multiple sclerosis.

 

Military :Stealthy Detection

Using gravimeter to detect opponent’s submarine. Radar signature may be hidden, but not for gravity. Rydberg atoms are boosted by lasers to unusually high energy levels, which greatly increase the atom’s sensitivity to electric fields. Identification of the electrical device to detect the affirmative or the opponent. The conventional method is to detect signals over a particular frequency in the electromagnetic spectrum, where Rydberg atoms are sensitive to a wide range of frequencies. They don’t absorb energy from the field that they measure, which can be used to detect signals without opponents realizing.

Reference:

1. https://www.bbc.com/news/business-47294704
2. https://www.birmingham.ac.uk/research/perspective/quantum-technology-underground.aspx
3. https://www.sussexquantum.com/optical-atomic-magnetometry
4. https://qtft.org/quantum-metrology-sensing-and-imaging/