Quantum sensors: gravity, magnetism and secure links

What have quantum sensing and quantum key distribution shown outside the laboratory so far?

Quantum sensors, quantum gravimetry and quantum key distribution have each reported field tests, flights or satellite experiments. The table sets out what each cited source reports, with the conditions and limitations stated there, one dimension at a time.

Quantum sensors: gravity, magnetism and secure links. Each cell shows a value, how well it is evidenced, and its sources.
Option	What it measures or protectsThe physical quantity measured, or the security property protected, and the quantum probe or method used.	Reported performanceThe reported figure, with its units and conditions: lab or field, year and scale.	Field deploymentsOutdoor, airborne or satellite tests reported, with what was tested and at what scale.	Main limitationThe limitation stated in the cited sources, where a source states one.
Quantum sensors	Time and magnetic fields, with atomic clocks and superconducting quantum interference device magnetometers given as examples in the review's abstract.Demonstrated[1]	No reliable public figure	May 2024 UK flight trials of quantum navigation technology on QinetiQ's RJ100 airborne technology demonstrator, at MoD Boscombe Down, with several test flights reported. The release names Infleqtion, BAE Systems and QinetiQ.Demonstrated[2]	The release gives no measured accuracy, timing or drift figures, and no flight durations, so the flight trials are reported without published performance figures.Reported, unverified[2]
Quantum gravimetry	Local gravity measurements from a quantum sensor, used to map buried voids such as a tunnel.Demonstrated[3]	Airborne absolute gravimetry (Bidel and colleagues, arXiv preprint, 2022): the abstract estimates measurement errors of 0.6 to 1.3 mGal for the quantum gravimeter, depending on flight conditions and filtering, against 3 to 4 mGal for the traditional platform gravimeter.Reported, unverified[4]	Outdoor survey (Stray and colleagues, 2022): detected a tunnel with a 2 metre by 2 metre internal cross-section, signal-to-noise ratio of about 8, over an 8.5 metre line at 0.5 metre spatial resolution.Demonstrated[3]	The paper states that conventional gravimeters are limited in measurement time by the need to average out micro-seismic vibration. It does not set out a remaining limitation of the quantum sensor itself.Reported, unverified[3]
Quantum key distribution	Creation of a secret key between authorised partners connected by a quantum channel, with an authenticated classical channel.Demonstrated[7]	Fibre experiment (Liu, 2023): secure key rate of 9.53 × 10^-12 per pulse over 1,002 km fibre in the asymptotic regime, and 8.75 × 10^-12 per pulse at 952 km with the finite-size effect considered.Demonstrated[6]	Satellite-to-ground link (Liao and colleagues, 2017): decoy-state QKD with a key rate over 1 kHz from a satellite to the ground over distances of up to 1,200 km.Demonstrated[5]	The UK NCSC does not endorse QKD for any government or military application, and cautions against sole reliance on QKD for business-critical networks (2020).Demonstrated[8]

Quantum sensors: gravity, magnetism and secure links. Each cell shows a value, how well it is evidenced, and its sources.

Option

What it measures or protectsThe physical quantity measured, or the security property protected, and the quantum probe or method used.

Reported performanceThe reported figure, with its units and conditions: lab or field, year and scale.

Field deploymentsOutdoor, airborne or satellite tests reported, with what was tested and at what scale.

Main limitationThe limitation stated in the cited sources, where a source states one.

Quantum sensors

Time and magnetic fields, with atomic clocks and superconducting quantum interference device magnetometers given as examples in the review's abstract.Demonstrated[1]

No reliable public figure

May 2024 UK flight trials of quantum navigation technology on QinetiQ's RJ100 airborne technology demonstrator, at MoD Boscombe Down, with several test flights reported. The release names Infleqtion, BAE Systems and QinetiQ.Demonstrated[2]

The release gives no measured accuracy, timing or drift figures, and no flight durations, so the flight trials are reported without published performance figures.Reported, unverified[2]

Quantum gravimetry

Local gravity measurements from a quantum sensor, used to map buried voids such as a tunnel.Demonstrated[3]

Airborne absolute gravimetry (Bidel and colleagues, arXiv preprint, 2022): the abstract estimates measurement errors of 0.6 to 1.3 mGal for the quantum gravimeter, depending on flight conditions and filtering, against 3 to 4 mGal for the traditional platform gravimeter.Reported, unverified[4]

Outdoor survey (Stray and colleagues, 2022): detected a tunnel with a 2 metre by 2 metre internal cross-section, signal-to-noise ratio of about 8, over an 8.5 metre line at 0.5 metre spatial resolution.Demonstrated[3]

The paper states that conventional gravimeters are limited in measurement time by the need to average out micro-seismic vibration. It does not set out a remaining limitation of the quantum sensor itself.Reported, unverified[3]

Quantum key distribution

Creation of a secret key between authorised partners connected by a quantum channel, with an authenticated classical channel.Demonstrated[7]

Fibre experiment (Liu, 2023): secure key rate of 9.53 × 10^-12 per pulse over 1,002 km fibre in the asymptotic regime, and 8.75 × 10^-12 per pulse at 952 km with the finite-size effect considered.Demonstrated[6]

Satellite-to-ground link (Liao and colleagues, 2017): decoy-state QKD with a key rate over 1 kHz from a satellite to the ground over distances of up to 1,200 km.Demonstrated[5]

The UK NCSC does not endorse QKD for any government or military application, and cautions against sole reliance on QKD for business-critical networks (2020).Demonstrated[8]

What the table shows

Quantum gravimetry reports a tunnel with a 2 metre by 2 metre internal cross-section detected in an outdoor survey, with a signal-to-noise ratio of about 8 (2022).
The airborne gravimetry preprint (2022) reports measurement errors of 0.6 to 1.3 mGal for the quantum gravimeter, against 3 to 4 mGal for a platform gravimeter. These figures are flagged for verification against the journal version.
Quantum key distribution cells give a fibre experiment over 1,002 km (2023) and a satellite-to-ground link over distances of up to 1,200 km (2017).
The reported-performance cell for quantum sensors is empty because the cited sources give no performance figure, and the 2024 UK release reports no accuracy figures.

Read with care

Each figure comes from one experiment or survey under its own conditions (lab fibre, airborne flight, outdoor survey, satellite pass), so the rows are not directly comparable.
Units differ between rows: QKD gives secure key rate per pulse, gravimetry gives measurement errors in mGal, and the field tests give sizes and key rates without a common metric.
The airborne gravimetry figures were checked in the arXiv preprint of the 2022 paper, not the published article, which could not be opened. They should be verified against the journal version before approval.
The sources show tests and experiments, not routine commercial service, for each row.

Sources

review article
Quantum sensing
C. L. Degen, F. Reinhard, P. Cappellaro. Reviews of Modern Physics, Jul 2017. Accessed 21 Oct 2026.
government report
Un-jammable quantum tech takes flight to boost UK's resilience against hostile actors
Department for Science, Innovation and Technology, 13 May 2024. Accessed 21 Oct 2026.
peer reviewed paper
Quantum sensing for gravity cartography
Ben Stray, Michael Holynski. Nature, Feb 2022. Accessed 21 Oct 2026.
preprint
Airborne absolute gravimetry with a quantum sensor, comparison with classical technologies
Yannick Bidel, Nassim Zahzam, Alexandre Bresson et al.. arXiv, Oct 2022. Accessed 21 Oct 2026.
preprint
Satellite-to-ground quantum key distribution
Sheng-Kai Liao, Jian-Wei Pan. arXiv, Jul 2017. Accessed 21 Oct 2026.
peer reviewed paper
Experimental Twin-Field Quantum Key Distribution over 1000 km Fiber Distance
Yang Liu. Physical Review Letters, 25 May 2023. Accessed 21 Oct 2026.
peer reviewed paper
The security of practical quantum key distribution
Valerio Scarani, Helle Bechmann-Pasquinucci, Nicolas J. Cerf et al.. Reviews of Modern Physics, 29 Sept 2009. Accessed 21 Oct 2026.
government report
Quantum security technologies
UK National Cyber Security Centre, 24 Mar 2020. Accessed 21 Oct 2026.