Precision Limits in Quantum Metrology with Open Quantum Systems

Understand

The laws of quantum mechanics allow to perform measurements whose precision supersedes results predicted by classical parameter estimation theory.

• That is, the precision bound imposed by the central limit theorem in the estimation of a broad class of parameters, like atomic frequencies in spectroscopy or external magnetic field in magnetometry, can be overcome when using quantum probes.
• Environmental noise, however, generally alters the ultimate precision that can be achieved in the estimation of an unknown parameter.
• This tutorial reviews recent theoretical work aimed at obtaining general precision bounds in the presence of an environment.