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Quamtum coherence between two atoms beyond Q=1015

Published

Author(s)

Chin-Wen Chou, David Hume, Michael J. Thorpe, David J. Wineland, Till P. Rosenband

Abstract

We place two atoms in quantum superposition states and observe coherent phase evolution for 3.4 × 1015 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 27Al+ ions, where a fractional uncertainty of 2.7 × 10−16 (extrapolated to 1 s measurement time) was observed. Two measures of the Q-factor are reported: The Q-factor derived from quantum coherence is 2.6 ± 1.1 × 1016 , and the spectroscopic Q-factor for a Ramsey time of 3 s is 6.7 × 1015. As part of this experiment, we demonstrate a method to detect the individual quantum states of two Al+ ions in an Al+ -Al+ -Mg+ linear ion chain without spatially resolving the ions.
Citation
Physical Review Letters
Volume
106

Keywords

Quantum coherence, Quality factor, Individual quantum state detection, Stability
Created April 22, 2011, Updated February 19, 2017