High-fidelity quantum state control of a polar molecular ion in a cryogenic environment
Abstract
We use a quantum-logic spectroscopy (QLS) protocol to control the quantum state of a CaH+ ion in a cryogenic environment, in which reduced thermal radiation extends rotational state lifetimes by an order of magnitude over those at room temperature. By repeatedly and adaptively probing the molecule, detecting the outcome of each probe via an atomic ion, and using a Bayesian update scheme to quantify confidence in the molecular state, we demonstrate state preparation and measurement (SPAM) in a single quantum state with infidelity less than 6x10^-3 and measure Rabi flopping between two states with greater than 99% contrast. The protocol does not require any molecule-specific lasers and the detection scheme is non-destructive.
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Cite
@article{arxiv.2506.14740,
title = {High-fidelity quantum state control of a polar molecular ion in a cryogenic environment},
author = {Dalton Chaffee and Baruch Margulis and April Sheffield and Julian Schmidt and April Reisenfeld and David R. Leibrandt and Dietrich Leibfried and Chin-Wen Chou},
journal= {arXiv preprint arXiv:2506.14740},
year = {2025}
}
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