Quantum coherence between two atoms beyond Q=10^15
Abstract
We place two atoms in quantum superposition states and observe coherent phase evolution for 3.4x10^15 cycles. Correlation signals from the two atoms yield information about their relative phase even after the probe radiation has decohered. This technique was applied to a frequency comparison of two Al+ ions, where a fractional uncertainty of 3.7+1.0-0.8x10^-16/\sqrt{\tau/s} was observed. Two measures of the Q-factor are reported: The Q-factor derived from quantum coherence is 3.4+2.4-1.1x10^16, and the spectroscopic Q-factor for a Ramsey time of 3 s is 6.7x10^15. As part of this experiment, we demonstrate a method to detect the individual quantum states of two Al+ ions in a Mg+-Al+-Al+ linear ion chain without spatially resolving the ions.
Cite
@article{arxiv.1101.3766,
title = {Quantum coherence between two atoms beyond Q=10^15},
author = {C. W. Chou and D. B. Hume and M. J. Thorpe and D. J. Wineland and T. Rosenband},
journal= {arXiv preprint arXiv:1101.3766},
year = {2015}
}
Comments
4 pages, 4 figures