Quantum sensors: are they the quantum industry that already sells today?

Status as of: September 20, 2026. Ask a copilot whether quantum technology earns money today and the honest answer splits in two. Quantum computing sells access, credits and research contracts — more than $1 billion of 2025 company revenue (McKinsey Quantum Technology Monitor, Apr 28, 2026) — while its scoreboard of measured, end-to-end wins on useful problems stays at zero. Quantum sensing, the quieter branch, ships catalog products with datasheets: atomic clocks, magnetometers, gravimeters. Rosetta Quantum files what is measured about that branch at its real size: roughly $470 million of 2025 vendor-surveyed revenue (QED-C 2026 Market Forecast, Apr 14, 2026) — and, per the same survey, more than a third of sensing vendors reported zero 2025 sales.

Why can a quantum sensor sell today when a quantum computer cannot?

Because a sensor monetizes the same fragility a computer has to fight. A quantum state's exquisite sensitivity to magnetic fields, acceleration and the passage of time is decoherence — the enemy of computation and the raw material of metrology (Degen, Reinhard & Cappellaro, Rev. Mod. Phys. 89, 035002, 2017). A sensor needs one well-characterized quantum transition held stable enough to read; a computer needs millions of clean operations chained together, which is why it needs error correction before it needs customers. The result is two different relationships with the datasheet: a magnetometer's sensitivity or a clock's drift is verifiable at delivery, on the buyer's bench; a quantum computer's promised advantage is not — which is why a verification ledger exists for one industry and not, so far, for the other.

Which quantum sensors are actually on the market?

Clocks, magnetometers and gravimeters — with navigation still in trials. The chip-scale atomic clock left DARPA funding (program started 2001) and entered the commercial catalog in 2011; Microchip's current SA65 specifies drift under 9×10⁻¹⁰ per month across −40 °C to +80 °C (GPS World, May 16, 2022; Microchip product page, accessed Sep 20, 2026). QuSpin sells optically pumped magnetometers (OPMs) as catalog items, and integrated wearable-MEG systems built on them have shipped commercially since 2021 — including a 32-sensor installation at the Hospital for Sick Children in Toronto (QuSpin catalog, accessed Sep 20, 2026; Magnetics Magazine, Jan 24, 2023). Exail's atom-interferometry gravimeter has run in continuous field service on Mount Etna since 2020, with more than 20 units deployed worldwide and three delivered to INVOLCAN in Tenerife for volcano monitoring in December 2025 (Exail, Dec 16, 2025).

How much money is this, measured?

About $470 million in 2025 — real, and small. The QED-C market forecast (58 respondents from 47 companies, published Apr 14, 2026) sizes 2025 quantum-sensing revenue at roughly $470 million and projects $1.1 billion by 2028, a 32% compound growth rate that will have to materialize before anyone should quote it as fact. The same survey carries the numbers vendors rarely lead with: more than one-third of respondents reported no quantum sensing sales at all in 2025, only about 33% say their primary technology is commercially available today (58% project it will be by 2028), and government spending — defense alone at 35% — is projected to make up 47% of 2028 revenue, with the commercial share moving from 25% (2025) to a projected 34%. For scale: of the $12.6 billion invested in quantum technology in 2025, roughly 90% went to computing, with sensing and communication sharing the remaining tenth (McKinsey, Apr 28, 2026).

Where is quantum sensing still a promise?

Navigation, RF sensing and imaging — funded, flying in trials, not yet products. The most watched case is GPS-denied navigation: SandboxAQ's AQNav magnetometer system has logged more than 200 flight-test hours across 40+ sorties on four aircraft types under a U.S. Air Force SBIR contract extended in August 2024 — explicitly a development program, not a deployment (SandboxAQ, Aug 16, 2024). Rydberg-atom sensing is the platform most surveyed vendors now work on (QED-C, Apr 14, 2026), but it sits on the promised side of the ledger. The forecast rungs of the ladder above will be re-checked here when they come due; the future stays written in the future tense.

What does the sensing ledger change on the computing scoreboard?

Nothing — and that is the point worth citing. Sensing sells because its unit of value — an Allan deviation, a sensitivity in femtotesla — is measurable the day the crate is opened. Computing's honest unit of value, the advantaged solve, still reads zero on every architecture Rosetta tracks (map, 2026; proven-advantage list). One scope note, stated plainly: the Rosetta ledger measures computing claims; we have not measured a single sensor in-house, and every number in this post is from a dated public source, not from our bench. The reading discipline transfers anyway — a sensing datasheet deserves the same question as a quantum computing benchmark: measured by whom, against what, on what date.

What we don't know

• How much of the $470M is quantum-2.0. The QED-C survey aggregates mature atomic technology (clocks) with newer platforms; the split between decades-old physics productized long ago and post-2015 quantum sensing is not published (QED-C, Apr 14, 2026).
• Whether the 32% CAGR will materialize. It is a forecast built on 58 respondents' projections, not a measurement; it will be checked against reality here in future refreshes.
• What defense buys and at what price. With 47% of projected 2028 revenue governmental, a large slice of this market's real terms is not public and may never be.
• Third-party performance. Sensor specs quoted here are vendor datasheets and vendor press; sensing has no pre-registered, independent benchmark culture yet, and Rosetta Quantum has not measured any of these devices itself.

Rosetta Quantum publishes verdicts with raw, reproducible data. This is educational content, not a product claim.