Towards quantum logic spectroscopy of multi-ion arrays*

We describe a new approach for precision spectroscopy of trapped ions using quantum logic. Our approach adapts method developed in the context of quantum information processing to non-destructive detection of the ¹S₀-³P₀ clock transition in ²⁷Al⁺. A state-dependent force is employed on the spectroscopy ion(s) to modulate the qubit state of the detection ion(s), similar to the techniques employed for high-fidelity quantum gates[1,2] and sensitive force detection experiments [3,4]. This method does not require ground state cooling and would enable scaling to large numbers of spectroscopy ions to improve ion clock stability.

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[2] D. Leibfried et al., Nature 422, 412 (2003).
[3] C. Hempel et al., Nature Photon. 7, 630 (2013).
[4] K. A. Gilmore et al., Phys. Rev. Lett. 118, 263602 (2017).