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Quantum Sensing Basics

BeginnerQuantum sensing5 min read

By QuantumO Editorial · Scientific reviewer: not yet assigned · Published · Updated

In short

Quantum sensing uses the sensitivity of quantum systems to measure time, magnetic and electric fields, gravity, and rotation with very high precision. It is the most commercially mature branch of quantum technology: atomic clocks and quantum magnetometers are already in everyday scientific and industrial use.

Fragility as a feature

Quantum states are easily disturbed. For computing that is a problem; for sensing it is the point. A carefully prepared state that shifts measurably in response to a tiny field makes an excellent detector.

Where it is already used

Atomic clocks underpin the definition of the second and the operation of satellite navigation. Quantum magnetometers are used in geophysics and in biomedical research. Atom interferometers are being tested for gravity mapping and navigation without satellites.

Common misconceptions

Claim: Quantum technology is entirely a future prospect.
More accurately: Quantum sensing and metrology are in routine use and underpin standards such as the SI definition of the second.

Important terminology

Coherence
Coherence is the property that lets a quantum system maintain well-defined relationships between its amplitudes, making interference possible.
Measurement
Measurement is the process that extracts a definite classical outcome from a quantum system, with probabilities set by its amplitudes.
Quantum state
A quantum state is the complete description of a quantum system, giving the amplitude of every possible measurement outcome.

Frequently asked questions

What is quantum sensing used for?
Precision timekeeping, magnetic and electric field measurement, gravity mapping, and navigation, among other applications.

Keep going

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The main qubit platforms and the engineering trade-offs between them.

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