Nearly 30 years ago, two-photon interference was observed, marking the beginning of a
new quantum era. Indeed, two-photon interference has no classical analogue, giving it a …

The statistical error in any estimation can be reduced by repeating the measurement and
averaging the results. The central limit theorem implies that the reduction is proportional to …

Quantum metrology is one of the most promising applications of quantum technologies. The
aim of this research field is the estimation of unknown parameters exploiting quantum …

Nonclassical states of light find applications in enhancing the performance of optical
interferometric experiments, with notable example of gravitational-wave detectors. Still, the …

The first quantum technology that harnesses quantum mechanical effects for its core
operation has arrived in the form of commercially available quantum key distribution …

Interferometric phase measurement is widely used to precisely determine quantities such as
length, speed and material properties,–. Without quantum correlations, the best phase …

Precision measurements can be brought to their ultimate limit by harnessing the principles of
quantum mechanics. In optics, multiphoton entangled states, known as NOON states, can be …

Among the applications of optical phase measurement, the differential interference contrast
microscope is widely used for the evaluation of opaque materials or biological tissues …

Quantum metrology employs quantum resources to enhance the measurement sensitivity
beyond that can be achieved classically. While multiphoton entangled N00N states can in …

On-chip integrated photonic circuits are crucial to further progress towards quantum
technologies and in the science of quantum optics. Here we report precise control of single …