2025-12-18 米国国立標準技術研究所（NIST）
＜関連情報＞
- https://www.nist.gov/news-events/news/2025/12/nist-physicists-bring-unruly-molecules-quantum-party
- https://journals.aps.org/prl/abstract/10.1103/7ypf-91jr
極低温環境における極性分子イオンの高忠実度量子状態制御 High-Fidelity Quantum State Control of a Polar Molecular Ion in a Cryogenic Environment
Dalton Chaffee, Baruch Margulis, April Sheffield, Julian Schmidt, April Reisenfeld, David R. Leibrandt, Dietrich Leibfried, and Chin-Wen Chou
Physical Review Letters Published 9 December, 2025
DOI: https://doi.org/10.1103/7ypf-91jr
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 6 ×10−3 and measure Rabi flopping between two states with greater than 99% contrast. The protocol does not require molecule-specific lasers and can be generalized, paving the way for high-fidelity quantum control of many other molecular ions.
