Polyatomic molecules have been identified as sensitive probes of charge-parity violating and parity-violating physics beyond the Standard Model (BSM). For example, many linear triatomic molecules are both laser-coolable and have parity doublets in the ground electronic $\tilde{X} {}^2Σ^+ (010)$ state arising from the bending vibration, both features that can greatly aid BSM searches. Understanding the $\tilde{X} {}^2Σ^+ (010)$ state is a crucial prerequisite to precision measurements with linear polyatomic molecules. Here, we characterize fundamental bending vibration of ${}^{174}$YbOH using high-resolution optical spectroscopy on the nominally forbidden $\tilde{X} {}^2Σ^+ (010) \rightarrow \tilde{A} {}^2Π_{1/2} (000)$ transition at 588 nm. We assign 39 transitions originating from the lowest rotational levels of the $\tilde{X} {}^2Σ^+ (010)$ state, and accurately model the state's structure with an effective Hamiltonian using best-fit parameters. Additionally, we perform Stark and Zeeman spectroscopy on the $\tilde{X} {}^2Σ^+ (010)$ state and fit the molecule-frame dipole moment to $D_\mathrm{mol}=2.16(1)$ D and the effective electron $g$-factor to $g_S=2.07(2)$. Further, we use an empirical model to explain observed anomalous line intensities in terms of interference from spin-orbit and vibronic perturbations in the excited $\tilde{A} {}^2Π_{1/2} (000)$ state. Our work is an essential step toward searches for BSM physics in YbOH and other linear polyatomic molecules.
Infrared absorption spectroscopy of a single polyatomic molecular ion
Institut für Experimentalphysik, Universität Innsbruck（因斯布鲁克大学实验物理研究所）；Department of Optics, Palacký University（帕尔察基大学光学系）；Faculty of Physics, University of Warsaw（华沙大学物理学院）
Spinor Bose-Einstein condensate as an analog simulator of molecular bending vibrations
Universitat Autònoma de Barcelona（巴塞罗那自治大学）；ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology（ICFO-光子科学研究所，巴塞罗那科学技术研究院）；Universitat de València-CSIC（瓦伦西亚大学-CSIC）
High-sensitivity molecular spectroscopy of SrOH using magneto-optical trapping
Harvard-MIT Center for Ultracold Atoms（哈佛-麻省理工学院超冷原子中心）；Department of Physics, Harvard University（哈佛大学物理系）；University of California, Berkeley（加州大学伯克利分校）；IonQ, Inc.（IonQ公司）
$\mathcal{P}$, $\mathcal{T}$-violating axion-mediated interactions in RaOH molecule
St. Petersburg State University（圣彼得堡国立大学）；Petersburg Nuclear Physics Institute named by B.P. Konstantinov of National Research Centre ”Kurchatov Institute”（俄罗斯国家研究中心库尔恰托夫研究所下属的B.P.康斯坦丁诺夫圣彼得堡核物理研究所）
