Simeonov Lachezar S, Vitanov Nikolay V, Ivanov Peter A
Department of Physics, St. Kliment Ohridski University of Sofia, 5 James Bourchier blvd, 1164, Sofia, Bulgaria.
Sci Rep. 2019 May 14;9(1):7340. doi: 10.1038/s41598-019-43865-5.
The quadrupole interaction between the Rydberg electronic states of a Rydberg ion and the radio frequency electric field of the ion trap is analyzed. Such a coupling is negligible for the lowest energy levels of a trapped ion but it is important for a trapped Rydberg ion due to its large electric quadrupole moment. This coupling cannot be neglected by the standard rotating-wave approximation because it is comparable to the frequency of the trapping electric field. We investigate the effect of the quadrupole coupling by performing a suitable effective representation of the Hamiltonian. For a single ion we show that in this effective picture the quadrupole interaction is replaced by rescaled laser intensities and additional Stark shifts of the Rydberg levels. Hence this detrimental quadrupole coupling can be efficiently compensated by an appropriate increase of the Rabi frequencies. Moreover, we consider the strong dipole-dipole interaction between a pair of Rydberg ions in the presence of the quadrupole coupling. In the effective representation we observe reducing of the dipole-dipole coupling as well as additional spin-spin interaction.
分析了里德堡离子的里德堡电子态与离子阱射频电场之间的四极相互作用。对于捕获离子的最低能级，这种耦合可以忽略不计，但由于捕获的里德堡离子具有较大的电四极矩，因此这种耦合很重要。由于这种耦合与捕获电场的频率相当，所以标准的旋转波近似不能忽略它。我们通过对哈密顿量进行适当的有效表示来研究四极耦合的影响。对于单个离子，我们表明在这个有效图景中，四极相互作用被重新缩放的激光强度和里德堡能级的附加斯塔克位移所取代。因此，通过适当增加拉比频率，可以有效地补偿这种有害的四极耦合。此外，我们考虑了在四极耦合存在的情况下一对里德堡离子之间的强偶极 - 偶极相互作用。在有效表示中，我们观察到偶极 - 偶极耦合的减小以及附加的自旋 - 自旋相互作用。
