In short
- Quantum sensing uses quantum states as the probe. Photons, electrons and atoms in superposition react to tiny changes in magnetic field, electric field, temperature, gravity or time.
- How it works. A field shifts the energy levels of the quantum system; the sensor turns that shift into a measurable frequency or phase.
- Strengths and limits. Unmatched precision and sensitivity, but quantum states are fragile and the hardware is complex.
- Where it is used. GPS-free navigation, medical imaging, environmental monitoring and secure communication.
Quantum sensing is set to redefine the limits of measurement and detection. This article explains its principles, its advantages and disadvantages, and its practical applications.
What is quantum sensing?
Quantum sensing uses the laws of quantum mechanics to measure physical quantities with a precision far beyond classical methods. Instead of the macroscopic properties of a system, it uses the quantum states of individual particles: photons, electrons and atoms.
Two quantum effects make this possible:
A quantum system can be in several states at once. A small external field changes the relative phase between those states, and that phase can be measured very precisely.
The properties of two or more particles are linked, even at a distance. Entangled probes can beat the noise limit of independent particles.
Together, these effects let quantum sensors detect minute changes in magnetic fields, electric fields, temperature and time. For a deeper look at why this is special, read What Makes Quantum Sensing So Special?
How does quantum sensing work?
Quantum magnetometers. In an atomic magnetometer, atoms are laser-cooled or optically pumped and placed in a superposition of spin states. An external magnetic field shifts their energy levels in proportion to the field strength (the Zeeman effect), so the spins precess at the Larmor frequency f = γ·B, where γ is the gyromagnetic ratio of the atom. Measuring the frequency or the accumulated phase gives the field intensity.
NV centers in diamond. A nitrogen-vacancy (NV) center is a point defect in the diamond lattice: one carbon atom is replaced by a nitrogen atom and the neighbouring lattice site is empty (a vacancy). NV centers are sensitive to magnetic and electric fields, temperature and pressure, and they work at room temperature. The sensor applies microwave pulses, illuminates the defect with green light and measures its red fluorescence, which changes with the spin state, to infer these quantities. Read more in Introduction to Quantum Sensing: NV Centers and Zeeman Splitting.
Quantum magnetometer calculator
Choose the spin system and enter the field, the interrogation time, the number of sensing spins and the readout contrast. The tool gives the Larmor frequency, the accumulated phase and the projection-noise (standard quantum limit) sensitivity.
f = γB, φ = 2πγBT, δB = 1 / (2πγ·T·C·√N) per measurement, and sensitivity η = δB·√T, assuming no dead time. Real sensors add photon shot noise, technical noise and decoherence, so treat the result as a best case.
Advantages and disadvantages
Quantum sensors detect changes in physical quantities far beyond the reach of classical sensors, opening new frontiers in science and technology.
They detect extremely weak signals, where traditional sensors would fail.
One approach measures many quantities, from gravity and gravitational waves to electric fields.
Sophisticated equipment and conditions, such as ultra-cold temperatures, stable lasers and magnetic shielding, make implementation complex and expensive.
Quantum states are very sensitive to environmental disturbances, which cause measurement errors without careful control.
Development and operation need deep expertise in quantum mechanics and engineering, which limits accessibility.
Practical applications
Quantum sensing is already used across many fields, showing its versatility and its potential to change industries:
Navigation and positioningsubmarines, spacecraft, GPS-denied areas
Quantum accelerometers and gyroscopes provide precise navigation without external signals, which is essential where GPS is unavailable.
Medical imagingMRI, brain and heart signals
Quantum sensors can improve the resolution and sensitivity of techniques such as MRI and magnetic recordings of the brain and heart, enabling earlier detection of disease.
Environmental monitoringgeophysics, water, atmosphere
Quantum sensors detect minute environmental changes, such as those linked to volcanic activity, groundwater levels and atmospheric conditions.
Telecommunicationssecure networks
Quantum techniques improve network security by revealing eavesdropping and help optimize signal transmission. See Quantum Entanglement: Nature’s Strangest Phenomenon in Technology.
Conclusion
Quantum sensing is a major step forward in measurement technology. Despite its challenges, its applications make it a key area for researchers and industry. As the technology matures and becomes more accessible, quantum sensing will play a growing role in shaping the future. For the bigger picture, read The Second Quantum Revolution.
Quantum sensing at IZAK Scientific
IZAK Scientific works on advancing quantum sensing technologies. Our expertise in electro-optics and photonics supports these applications, and we offer engineering services to companies that are taking their first steps into quantum technology.
Our team of physicists and engineers develops custom sensors, inspection systems and testers for applications such as environmental monitoring and secure telecommunications: optics and laser alignment, low-noise detection, timing electronics and control software. We work with our clients from the first concept through to deployment.
Partnering with IZAK Scientific gives you access to state-of-the-art quantum sensing know-how. Get in touch to discuss how quantum sensing can serve your application.
IZAK products for this application
Instruments from our catalog that match the measurements and set-ups in this article.
Quantum opticsQuantumAlign NLO Kinematic StagePosition nonlinear crystals with X–Y translation, tip and tilt.View product →
Laser metrologyLaser Beam ProfilersUV to LWIR families, packaged, OEM or software, with Test mode and reports.View product →
Optical powerMulti-Channel Power MeterParallel optical power on several fiber-coupled channels, with logging software.View product →Need something that is not in the catalog? We design custom electro-optical systems →
Frequently asked questions
QWhat is quantum sensing?
QHow does a quantum magnetometer work?
QWhat limits the sensitivity of a quantum sensor?
Tzachi Sabati
CEO, IZAK Scientific
Physicist specializing in photonics and quantum technologies, with deep expertise in quantum sensors and advanced optical systems. Leads the Advanced Quantum Lab course at the Technion, bridging academic excellence with industry innovation. At IZAK Scientific, provides cutting-edge photonics-based solutions, developing customized inspection and sensing systems for R&D and production. Passionate about advancing quantum sensing applications and integrating novel technologies to meet industry needs.
