Quantum sensing has become a broad field. It is generally related with the idea of using
quantum resources to boost the performance of a number of practical tasks, including the …

In the past 20 years, impressive progress has been made both experimentally and
theoretically in superconducting quantum circuits, which provide a platform for manipulating …

Many-particle entanglement is a key resource for achieving the fundamental precision limits
of a quantum sensor. Optical atomic clocks, the current state of the art in frequency precision …

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 …

“Quantum sensing” describes the use of a quantum system, quantum properties, or quantum
phenomena to perform a measurement of a physical quantity. Historical examples of …

Quantum technologies exploit entanglement to revolutionize computing, measurements, and
communications. This has stimulated the research in different areas of physics to engineer …

The production of pairs of entangled photons simply by focusing a laser beam onto a crystal
with a nonlinear optical response was used to test quantum mechanics and to open new …

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 …

We summarize important recent advances in quantum metrology, in connection to
experiments in cold gases, trapped cold atoms and photons. First we review simple …

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 …