39K(2) 2(3)Σ(g)+态：观测与分析

The 39K(2) 2(3)Sigma(g)+ state: observation and analysis.

作者信息

Li Dan, Xie Feng, Li Li, Sovkov Vladimir B, Ivanov Valery S, Ahmed Ergin, Lyyra A Marjatta, Huennekens John, Magnier Sylvie

机构信息

Key Laboratory of Atomic and Molecular Nanosciences, Department of Physics, Tsinghua University, Beijing 100084, China.

出版信息

J Chem Phys. 2007 May 21;126(19):194314. doi: 10.1063/1.2730804.

DOI:10.1063/1.2730804

PMID:17523811

Abstract

The (39)K(2) 2 (3)Sigma(g) (+) state has been observed by perturbation-facilitated infrared-infrared double resonance spectroscopy and two-photon excitation. Resolved fluorescence spectra into the a (3)Sigma(u) (+) state have been recorded. The observed vibrational levels have been assigned as the v=23-25, 27, 28, 31-33, 38-45, 47, and 53 levels by comparing the observed and calculated spectra of the 2 (3)Sigma(g) (+)-->a (3)Sigma(u) (+) transitions. Molecular constants have been obtained using a global fitting procedure with a comprehensive set of experimental data. Fine and hyperfine splittings have been resolved in the excitation spectra. Perturbations between the 2 (3)Sigma(g) (+) and 2 (3)Pi(g) states were observed. The hyperfine patterns of the 2 (3)Sigma(g) (+) levels are strongly affected by the perturbation. The perturbation-free and weakly perturbed levels follow the case b(betaS) coupling scheme, while the perturbed levels follow case b(beta J) coupling. A Fermi contact constant, b(F)=65+/-10 MHz, has been obtained. Intensity anomalies of rotational lines appeared both in the 2 (3)Sigma(g) (+) approximately 2 (3)Pi(g)<--b (3)Pi(u) excitation spectra and in the 2 (3)Sigma(g) (+) approximately 2 (3)Pi(g)-->a (3)Sigma(u) (+) resolved fluorescence spectra. These intensity anomalies can be explained in terms of a quantum-mechanical interference effect.

摘要

通过微扰促进红外-红外双共振光谱和双光子激发观测到了(39)K(2) 2 (3)Σ(g) (+)态。记录了分辨到a (3)Σ(u) (+)态的荧光光谱。通过比较2 (3)Σ(g) (+)-->a (3)Σ(u) (+)跃迁的观测光谱和计算光谱，将观测到的振动能级指定为v = 23 - 25、27、28、31 - 33、38 - 45、47和53能级。使用全局拟合程序和一组全面的实验数据获得了分子常数。在激发光谱中分辨出了精细和超精细分裂。观测到了2 (3)Σ(g) (+)和2 (3)Π(g)态之间的微扰。2 (3)Σ(g) (+)能级的超精细模式受到微扰的强烈影响。无微扰和弱微扰能级遵循情况b(βS)耦合方案，而受微扰能级遵循情况b(βJ)耦合。获得了费米接触常数b(F)=65±10 MHz。在2 (3)Σ(g) (+)≈2 (3)Π(g)<--b (3)Π(u)激发光谱和2 (3)Σ(g) (+)≈2 (3)Π(g)-->a (3)Σ(u) (+)分辨荧光光谱中均出现了转动线的强度异常。这些强度异常可以用量子力学干涉效应来解释。