We show that the statistical properties of a Coulomb crystal can be measured by means of a standard interferometric procedure performed on the spin of one ion in the chain. The ion spin, constituted by two internal levels of the ion, couples to the crystal modes via spatial displacement induced by photon absorption. The loss of contrast in the interferometric signal allows one to measure the autocorrelation function of the crystal observables. Close to the critical point, where the chain undergoes a second-order phase transition to a zigzag structure, the signal gives the behaviour of the correlation function at the critical point.
@article{arxiv.0807.2212,
title = {Ramsey interferometry with a spin embedded in a Coulomb chain},
author = {Gabriele De Chiara and Tommaso Calarco and Shmuel Fishman and Giovanna Morigi},
journal= {arXiv preprint arXiv:0807.2212},
year = {2008}
}
Comments
12 pages, 9 figures. Changes: typical experimental parameters + minor corrections. Published version