Event Details

In these two lectures, the foundations and recent results of quantum metrology will be presented. Quantum mechanics imposes limits on the precision of measurements, due to the Heisenberg uncertainty relations, but also allows one to explore the use of quantum states to surpass the precision obtained with classical strategies. Two distinct aspects will be discussed: 1. How to determine the ultimate precision limit in the estimation of a parameter, which could be for instance the variation in length or phase of an interferometer, a small rotation of a mirror, the transition frequency of an atom, the time duration of a dynamical process, or a weak electric or magnetic field; 2. The connection of quantum metrology with number-phase and energy-time uncertainty relations. Lecture 1 introduces the Fisher information, discusses its geometrical meaning, and reviews recent experiments that have led to improved precision beyond the quantum standard limit. Lecture 2 extends these ideas to open systems, applying them to noisy interferometers and to a generalization for noisy systems of the Mandelstam-Tamm energy-time uncertainty relation.