Not the same as quantum computing
Quantum computers aim to process information in new ways. Quantum sensors do something simpler and often closer to market: they exploit the fact that quantum systems are extremely sensitive to their environment, which makes them excellent measuring tools.
Kinds of quantum sensor
Atomic clocks keep time far more accurately than quartz. Cold-atom interferometers measure acceleration and rotation, and gravity gradients. Sensors based on nitrogen-vacancy centres in diamond, or on optically pumped atoms, detect very small magnetic fields, including those from the human brain and heart.
What they could change
Navigation that keeps working when satellite signals are jammed or unavailable, by combining precise clocks and inertial sensors. Mapping of underground water, minerals and tunnels from gravity differences. Lighter, cheaper brain-imaging systems. Most of these are moving from laboratories into early field trials, so costs, size and robustness remain the main questions.
Where it is used
- Timekeeping Atomic clocks for networks and navigation.
- Navigation Inertial sensing where satellite signals are unavailable.
- Geoscience Gravity and magnetic surveys of ground and water.
- Medicine Magnetic sensing of activity in the brain and heart.
Quantum sensing compared with quantum computing and classical sensors
Quantum computing aims to solve certain calculations faster. Quantum sensing aims to measure better. A sensor needs only a few well-controlled quantum systems, not the thousands of fragile qubits a useful computer would need, which is why some quantum sensors are already in use.
Compared with classical sensors, quantum ones can be more precise or more stable, but today they are usually larger, costlier and harder to run outside a laboratory.
Key terms
- Atomic clock
- A clock that keeps time by the frequency of atoms.
- Interferometer
- An instrument that measures tiny differences by comparing waves.
- Magnetometer
- A sensor for magnetic fields.
- Inertial navigation
- Working out position from movement measured since a known start.
Common questions
Is quantum sensing the same as quantum computing?
- No. They share physics but have different goals and different levels of maturity. Sensing is generally closer to practical use.
How can it navigate without GPS?
- By measuring movement very precisely from a known start, using accurate accelerometers, gyroscopes and clocks, a method called inertial navigation.
When will quantum sensors be common?
- Some, such as atomic clocks, already are in specialist use. Others are in trials, and wider adoption depends on size and cost.
Sources and further reading
Independent pages we checked while writing this guide. They are not Reinnder products, and Reinnder is not affiliated with them.
Reinnder’s angle
How Reinnder looks at quantum sensing
Reinnder Labs lists quantum sensing as a long-horizon research interest.
This guide explains the technology in general terms. It is not advice, and it does not describe a Reinnder product on sale.