GCRI · Quantum Technologies
Quantum sensing
Quantum sensors use the sensitivity of quantum states to measure time, magnetic fields, gravity, acceleration and rotation with high precision. Atomic clocks already underpin navigation and networks; newer sensors could support navigation without satellites, medical imaging and underground mapping. This page sets out how quantum sensing works, how mature each application is, and what evidence serves the agencies and industries considering it.
Quantum sensing in seven parts.
- 01The questionQuantum sensing: how the risk develops
- 02Across the domainsQuantum sensors could change measurement in several domains
- 03IndicatorsWhat is measured, and how well
- 04SourcesWhere the evidence comes from
- 05DecisionsWho decides, and what the evidence serves
- 06Core questionsWhat experts ask
- 07MechanismsMechanisms and drivers
Quantum sensing: how the risk develops.
Measurement, navigation and Earth-science applications. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Atoms keep precise time
Atomic clocks use transitions between atomic energy levels as frequency references. They underpin satellite navigation, telecommunications and financial timestamps.
Interference measures motion and gravity
Atom interferometers split and recombine matter waves to measure acceleration, rotation and gravity, with potential for navigation and subsurface mapping.
Defects sense magnetic fields
Defects in diamond and other systems sense tiny magnetic fields at small scales, with uses in materials science and biology.
Field use is hard
Laboratory sensitivity often degrades in the field because of vibration, temperature and size constraints. Ruggedising sensors is a major engineering challenge.
Quantum testbed.
The screen a team would use to follow this subject: its measures, states and decisions. Names are examples and values are illustrative.
Quantum testbed
Quantum sensing · Testbed lab · Device QD-91
Qubits
| Q0 | 166 | 94 | 0.02 | In spec |
| Q1 | 102 | 35 | 0.04 | In spec |
| Q2 | 178 | 57 | 0.05 | Drifting |
| Q3 | 62 | 32 | 0.02 | In spec |
| Q4 | 100 | 95 | 0.03 | Drifting |
Device
- Topology
- heavy-hex, illustrative
- 2Q fidelity
- 0.994
- Access
- by committee
- Label
- OBSERVED
Quantum sensors could change measurement in several domains.
- WaterCouplingQuantum gravimeters could improve subsurface monitoring.What to watchField performance against conventional gravimeters
- EnergyCouplingPrecise timing and magnetometry support grid monitoring.What to watchTiming holdover without satellites
- HealthCouplingQuantum magnetometers are studied for medical imaging.What to watchClinical validation stage
Sensing evidence is designed for the Labs Evidence series. Field results are reported with conditions; laboratory sensitivity is not field performance.
- Field trial results with conditions.
- Comparisons against classical sensors.
How quantum sensing is modelled, measured and tested.
The model, its assumptions, its data and its uncertainty, in the form a scientist or engineer would check. Structures follow published methods. The values drawn are illustrative, not findings.
System model
The couplings between the systems in quantum sensing: signs of influence, a reinforcing and a balancing loop, and cross-links where stress jumps.
What is measured, and how well.
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Clock fractional frequency uncertainty | dimensionless | per publication | Metrology institute results | OBSERVED |
| Sensor sensitivity | units per square root of hertz | per device | Published characterisation | REPORTED |
| Field trials of quantum navigation | count | annual | Agency and research reports | REPORTED |
| Technology readiness level by application | readiness level | per assessment | Expert assessments | ESTIMATED |
| Size, weight and power of deployed sensors | kilograms and watts | per device | Product specifications | DECLARED |
| Commercially available quantum sensor products | count by type | annual | Market surveys | REPORTED |
Where the evidence comes from.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| BIPM and national metrology institute publications | Time standards and clock comparisons | Public, terms per institute |
| Peer-reviewed sensing literature | Experimental sensitivities and demonstrations | Licence per article |
| Defence and transport agency reports on alternative navigation | Assessments of quantum navigation options | Public, terms per agency |
| OECD quantum technologies policy work | Overview of sensing applications and policy | Public, OECD terms |
| Market surveys of quantum sensing | Products and firms | Commercial; public summaries (to check) |
Who decides, and what the evidence serves.
Quantum Technologies prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| Transport and navigation authorities | Whether quantum sensors can reduce dependence on satellite navigation | Readiness assessments; field trial evidence |
| Metrology institutes | How to develop and disseminate time and frequency standards | Clock performance evidence |
| Industry and health systems | Where quantum sensors offer practical benefit | Application comparisons |
Outputs this topic produces
- Readiness assessments by sensing application
- Comparisons of quantum and classical sensor options
- Evidence notes on navigation resilience
- Field trial review frameworks
What experts ask.
Sensing questions concern precision, robustness and use outside the laboratory.
- How much better than classical instruments is a quantum sensor in real operating conditions?
- Can it be made small, robust and affordable enough for field use?
- Could quantum inertial sensors and clocks provide navigation when satellite signals are lost or jammed?
- What could quantum gravimeters and magnetometers reveal about groundwater, geology and infrastructure?
- What are the dual-use implications, for example for detecting submarines or underground structures?
Mechanisms and drivers.
Quantum sensors exploit the fact that quantum states are disturbed by tiny changes in their environment. Atomic clocks measure time by the frequency of atomic transitions. Atom interferometers split and recombine clouds of cold atoms to measure acceleration and gravity. Defects in diamond and other materials act as nanoscale magnetometers. The same sensitivity that gives precision also makes sensors vulnerable to noise, vibration and temperature changes.
The step from laboratory to field is the main challenge. Many quantum sensors require lasers, vacuum systems and careful isolation. Engineering progress is reducing size and power, but performance in a moving vehicle or harsh environment is often well below laboratory results.
How it is studied, and where the methods stop.
| Method or data | What it shows | Limits |
|---|---|---|
| Laboratory metrology | Fundamental sensitivity and stability | Laboratory performance rarely transfers directly to the field |
| Field trials | Performance in vehicles, aircraft, boreholes or ships | Few trials, often reported by developers |
| Comparison with classical sensors | Whether the quantum device adds real value | Classical sensors also improve |
| Earth observation data fusion | Combining quantum gravimetry with satellite and ground data | Interpretation depends on geophysical models |
How it is studied, and what the methods cannot say.
- 01Physics and quantum scienceCharacterising qubit noise · Metrology of quantum clocks · Verifying quantum effectsApplied here
- 02Quantum computing, sensing and communicationComparable benchmarking · Technology readiness assessment · Security implications trackingApplied here
- 03Probability and statisticsFidelity estimation · Testing advantage claims · Analysing patent and investment dataApplied here
- 04Materials science and chemistryMaterials for longer coherence · Fabrication variability · Quantum chemistry use casesApplied here
Where this page’s references lead.
The bodies and documents this page is read against. Status and editions change; each link goes to the issuing body.
Questions and answers.
What is a quantum sensor?
Are atomic clocks quantum technology?
Can quantum sensors replace GPS?
Is quantum sensing already in use?
Could quantum sensors replace satellite navigation?
Why is sensing considered dual use?
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