LaserLaB, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Phys Chem Chem Phys. 2011 Nov 14;13(42):18844-51. doi: 10.1039/c1cp21204d. Epub 2011 Jul 13.
A calculation of dynamic polarizabilities of rovibrational states with vibrational quantum number v = 0-7 and rotational quantum number J = 0,1 in the 1sσ(g) ground-state potential of HD(+) is presented. Polarizability contributions by transitions involving other 1sσ(g) rovibrational states are explicitly calculated, whereas contributions by electronic transitions are treated quasi-statically and partially derived from existing data [R. E. Moss and L. Valenzano, Mol. Phys., 2002, 100, 1527]. Our model is valid for wavelengths >4 μm and is used to assess level shifts due to the blackbody radiation (BBR) electric field encountered in experimental high-resolution laser spectroscopy of trapped HD(+) ions. Polarizabilities of 1sσ(g) rovibrational states obtained here agree with available existing accurate ab initio results. It is shown that the Stark effect due to BBR is dynamic and cannot be treated quasi-statically, as is often done in the case of atomic ions. Furthermore it is pointed out that the dynamic Stark shifts have tensorial character and depend strongly on the polarization state of the electric field. Numerical results of BBR-induced Stark shifts are presented, showing that Lamb-Dicke spectroscopy of narrow vibrational optical lines (∼10 Hz natural linewidth) in HD(+) will become affected by BBR shifts only at the 10(-16) level.
本文呈现了对 HD(+) 1sσ(g)基态势能中振动量子数 v = 0-7 和转动量子数 J = 0,1 的 rovibrational 态的动态极化率的计算。明确计算了涉及其他 1sσ(g)rovibrational 态的跃迁的极化率贡献，而电子跃迁的贡献则采用准静态处理，并部分源自现有数据[R. E. Moss 和 L. Valenzano，Mol. Phys.，2002，100，1527]。我们的模型适用于 >4 μm 的波长，用于评估在被困 HD(+)离子的实验高分辨率激光光谱中遇到的黑体辐射（BBR）电场引起的能级位移。这里获得的 1sσ(g)rovibrational 态的极化率与现有的准确从头算结果一致。结果表明，由于 BBR 引起的斯塔克效应是动态的，不能像原子离子那样进行准静态处理。此外，还指出动态斯塔克位移具有张量特性，并强烈依赖于电场的偏振状态。呈现了 BBR 引起的斯塔克位移的数值结果，表明仅在 10(-16)水平，HD(+)中窄振动光学线（~10 Hz 自然线宽）的 Lamb-Dicke 光谱才会受到 BBR 位移的影响。
