Traditional Ramsey spectroscopy has the frequency resolution 2π/T, where T is the time separation between two light fields. Using squeezed states and two-atom excitation joint detection, we present a new scheme achieving a higher resolution π/T. We use two mode squeezed light which exhibits strong entanglement.
@article{arxiv.1304.4323,
title = {Ramsey spectroscopy with squeezed light},
author = {Kenan Qu and G. S. Agarwal},
journal= {arXiv preprint arXiv:1304.4323},
year = {2015}
}