Seminarium Optyczne

The strong sensitivity of certain quantum states to small variations of external parameters opens up great opportunities for devising high-precision measurements with unprecedented accuracy. A particularly important physical measurement technique is interferometry which has countless applications in science and technology. Understanding limits on its performance in realistic situations is therefore of great importance.In this talk I will present possibilities for improved phase estimation in optical and atomic (Ramsey type) interferometry using highly non-classical input states. In particular, this will include a discussion of the fundamental limits of the achievable precision in the presence of noise which is experimentally unavoidable and threatens to destroy the employed quantum state and therefore potential improvements in precision. The quantum states corresponding to these limits thus represent an optimal trade-off between robustness with respect to noise and quantum improvement in phase estimation. I will furthermore discuss alternative states and strategies leading to slightly smaller precision but which are potentially easier to implement and therefore more relevant for experiments.