quantumsensing

Quantum sensing is a field within quantum metrology that uses quantum systems, states, and dynamics to measure physical quantities with precision beyond what classical strategies can achieve. By exploiting quantum coherence, entanglement, and squeezing, quantum sensing aims to reduce the uncertainty in an estimated parameter, such as a magnetic field, temperature, time, or acceleration.

The sensitivity of a sensor is often bounded by the standard quantum limit, which arises from quantum projection noise. Employing nonclassical probes—entangled states, spin-squeezed ensembles, or squeezed light—can improve scaling with resources and, in idealized cases, approach the Heisenberg limit. In real devices, decoherence, technical noise, and imperfect readout limit achievable gains.

Common platforms include atomic clocks and atom interferometers for time and inertial sensing, nitrogen-vacancy centers in diamond for nanoscale magnetic field sensing, trapped ions and cold atoms for magnetometry and gravimetry, and superconducting circuits for electromagnetic field sensing. Applications span navigation and inertial sensing, geophysics, fundamental physics tests, and biomedical imaging.

Research continues to develop robust, miniaturized sensors and hybrid systems that integrate quantum probes with classical readout. While still maturing, quantum sensing has demonstrated record sensitivities and is transitioning from laboratory demonstrations to field deployments and industrial use.