# Quantum sensing use cases

Real-world applications of quantum magnetometers, gravimeters, atomic clocks and inertial sensors in defense, healthcare, navigation and resource exploration.

Updated 2026-11-01. Also on the [web page](https://quantumcompanies.fyi/guides/quantum-sensing-use-cases).

Quantum sensors exploit superposition, entanglement and quantum interference to measure magnetic fields, gravity, time, rotation and acceleration with sensitivity beyond classical limits.

## Sensor types and commercial maturity

| Sensor type | Physical principle | Leading vendors | Maturity | Typical sensitivity |
|---|---|---|---|---|
| **NV-diamond magnetometer** | Nitrogen-vacancy center spin | QZabre, Quantum Diamonds, SBQuantum | Commercial | ~pT/√Hz (room temp) |
| **SERF/OPM magnetometer** | Spin-exchange relaxation-free alkali vapor | QuSpin, FieldLine, Cerca Magnetics | Commercial | ~fT/√Hz (body temp) |
| **SQUID magnetometer** | Superconducting quantum interference | Tristan Technologies, STAR Cryoelectronics | Commercial (cryogenic) | ~fT/√Hz (4 K) |
| **Cold-atom gravimeter** | Atom interferometry (Rb/Cs) | Muquans (iXblue), AOSense, ColdQuanta (Infleqtion) | Pilot/early commercial | ~1–10 nm/s² (μGal) |
| **MEMS gravimeter** | Silicon MEMS + quantum readout | Silicon Microgravity, Glasgow Univ. spinout | Emerging | ~10–100 μGal |
| **Chip-scale atomic clock (CSAC)** | Coherent population trapping (Cs/Rb) | Microchip (Microsemi), AccuBeat, IQD | Commercial (volume) | 1e-11 to 1e-12 / day |
| **Cold-atom clock** | Ramsey/Rabi interrogation (Sr/Yb) | VREMYA, NICT, NIST spinouts | Research/defense | < 1e-15 / day |
| **Cold-atom inertial (accel/gyro)** | Atom interferometry | AOSense, ColdQuanta, M Squared, iXblue | Pilot (defense/space) | ~1–10 ng/√Hz, ~0.001 °/hr |
| **Quantum RNG** | Photon shot noise, vacuum fluctuations | ID Quantique, QuintessenceLabs, Quantum Dice, Quside | Commercial | Gbps rates, NIST SP 800-90B validated |

## Key use cases by sector

### Defense & national security
- **Submarine detection**: NV and SERF magnetometers for magnetic anomaly detection (MAD) without cryogenics.
- **GPS-denied navigation**: Cold-atom accelerometers/gyros for inertial navigation on aircraft, ships, satellites.
- **Secure communications**: Quantum RNGs for key generation; QKD for link encryption.
- **Underground facility mapping**: Quantum gravimeters detect density anomalies (tunnels, bunkers).

### Healthcare & life sciences
- **Magnetoencephalography (MEG)**: OPM/SERF sensors enable wearable, room-temp MEG helmets for epilepsy and brain research (FieldLine, Cerca Magnetics).
- **Magnetocardiography (MCG)**: Fetal and adult cardiac magnetic field mapping without shielding.
- **Drug discovery**: NV-diamond nanoscale NMR for single-protein structure determination.

### Energy & resources
- **Mineral exploration**: Quantum gravimeters and magnetometers on drones/aircraft for ore body detection. Ask vendors for named reference deployments.
- **Oil & gas reservoir monitoring**: Time-lapse gravity for fluid movement tracking.
- **Carbon capture verification**: Gravimetric monitoring of CO₂ plume migration.
- **Pipeline inspection**: NV magnetometers for corrosion and defect mapping.

### Navigation & timing
- **Autonomous vehicles**: CSAC for holdover when GNSS denied; cold-atom IMU for long-duration dead reckoning.
- **Telecom & financial networks**: CSAC and quantum clocks for 5G synchronization, high-frequency trading timestamping.
- **Space**: Cold-atom clocks (ACES/PHARAO on ISS) and interferometers for geodesy, fundamental physics.

### Industrial & manufacturing
- **Non-destructive testing**: NV magnetometry for current imaging in batteries, semiconductors, composites.
- **Quality control**: Quantum gravimeters for density variation detection in additively manufactured parts.

## Procurement considerations

- **SWaP-C**: Size, weight, power and cost. CSACs are chip-scale (< 20 cm³, < 120 mW). Cold-atom systems are rack-mount (19", 100–500 W).
- **Environmental**: Vibration, magnetic shielding, temperature stability. SERF/OPM needs μT-level shielding. Cold-atom needs vibration isolation.
- **Export controls**: High-performance magnetometers (ECCN 6A006), gravimeters and gradiometers (ECCN 6A007) and inertial navigation systems (EAR Category 7) may be controlled; some items can fall under ITAR. Confirm the classification with BIS or counsel before export.
- **Integration**: Digital output (UART, SPI, Ethernet), SDKs (Python, C++, ROS), time synchronization (PTP, NTP).
- **Support**: Calibration services, MTBF, warranty, US/EU manufacturing for defense supply chain.

## Sources

- [FieldLine OPM-MEG](https://fieldlineinc.com/) — fetched 2026-11-01.
- [Cerca Magnetics](https://cercamagnetics.com/) — fetched 2026-11-01.
- [Muquans (iXblue) quantum gravimeters](https://www.muquans.com/) — fetched 2026-11-01.
- [AOSense cold-atom sensors](https://aosense.com/) — fetched 2026-11-01.
- [Infleqtion (ColdQuanta) quantum sensors](https://infleqtion.com/) — fetched 2026-11-01.
- [Microchip CSAC](https://www.microchip.com/en-us/products/timing-and-synchronization/atomic-clocks) — fetched 2026-11-01.
- [ID Quantique QRNG](https://www.idquantique.com/random-number-generation/) — fetched 2026-11-01.
- [SBQuantum NV magnetometers](https://sbquantum.com/) — fetched 2026-11-01.
- [QZabre NV diamond sensors](https://qzabre.com/) — fetched 2026-11-01.
- [DARPA AMIIMO / ROAMS programs](https://www.darpa.mil/program/atomic-microsystems-for-inertial-measurement) — fetched 2026-11-01.

## Questions

### Are quantum sensors commercially available today?

Yes. NV-diamond magnetometers, chip-scale atomic clocks (CSAC), MEMS gravimeters and quantum RNGs are shipping. Neutral-atom gravimeters and cold-atom inertial sensors are in late-stage pilots with defense and energy customers.

### What is the price range?

Prices are quoted per order and vary with volume and options — chip-scale atomic clocks are the cheapest class and cold-atom inertial systems the most expensive. Ask each vendor for a current quote.

### Do quantum sensors need cryogenics?

Most commercial quantum sensors operate at room temperature or with compact thermoelectric cooling. Only the highest-sensitivity research systems (SQUIDs, some NV centers) require liquid helium or dilution refrigeration.