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Coherently displaced oscillator quantum states of a single trapped atom



Katherine C. McCormick, Jonas Keller, David J. Wineland, Andrew C. Wilson, Dietrich Leibfried


Coherently displaced harmonic oscillator number states of a harmonically bound ion can be coupled to two internal states of the ion by a laser-induced motional sideband interaction. The internal states can subsequently be read out in a projective measurement via state-dependent fluorescence, with near-unit fidelity. This leads to a rich set of line shapes when recording the internal-state excitation probability after a sideband excitation, as a function of the frequency detuning of the displacement drive with respect to the ion's motional frequency. We precisely characterize the coherent displacement based on the resulting line shapes, which exhibit sharp features that are useful for oscillator frequency determination from the single quantum regime up to very large coherent states with average occupation numbers of several hundred. We also introduce a technique based on multiple coherent displacements and free precession for characterizing noise on the trapping potential in the frequency range of 500 Hz to 400 kH.
Quantum Science and Technology


coherent displacements, frequency noise, harmonic oscillator, trapped ion


McCormick, K. , Keller, J. , Wineland, D. , Wilson, A. and Leibfried, D. (2019), Coherently displaced oscillator quantum states of a single trapped atom, Quantum Science and Technology, [online],, (Accessed June 21, 2024)


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Created June 11, 2019, Updated July 27, 2022