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arXiv · 2610.07680

Spectroscopy using dipole-phonon quantum logic

Lu Qi·Evan C. Reed·Duanyang Wang·Boyan Yu·Kenneth R. Brown
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Abstract

Dipole-phonon quantum logic (DPQL) offers novel approaches for state preparation, measurement, and control of quantum information in molecular ion qubits. Here we report the first experimental demonstration of DPQL as a spectroscopic tool using the shared motional mode of a CaO$^+$-Ca$^+$ ion chain to measure the frequency splitting of the ground $Ω$-doublet of CaO$^+$. By comparing the dipole-phonon signal across three trap-frequency ramp ranges, we determine the splitting to be $ω_{mol}=2π\times454\pm1$ kHz and place a lower bound on the effective dipole-phonon coupling. The rate of observation is limited by the low thermal population in the molecular ground rotational state.

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Lu Qi, Evan C. Reed, Duanyang Wang, Boyan Yu, Kenneth R. Brown. 2026-10-06. Spectroscopy using dipole-phonon quantum logic. https://arxiv.org/abs/2610.07680

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