Department of Physics and Astronomy, University of Delaware, Newark, DE, USA.
IEEE Trans Ultrason Ferroelectr Freq Control. 2012 Mar;59(3):439-47. doi: 10.1109/TUFFC.2012.2213.
A review of recent theoretical calculations of blackbody radiation (BBR) shifts in optical atomic clocks is presented. We summarize previous results for monovalent ions that were obtained by a relativistic all-order single-double method, where all single and double excitations of the Dirac- Fock wave function are included to all orders of perturbation theory. A recently developed method for accurate calculations of BBR shifts in divalent atoms is then presented. This approach combines the relativistic all-order method and the configuration interaction method, which provides for accurate treatment of correlation corrections in atoms with two valence electrons. Calculations of the BBR shifts in B+, Al+, and In+ have enabled us to reduce the present fractional uncertainties in the frequencies of their clock transitions as measured at room temperature: to 4 × 10-19 for Al+ and 10-18 for B+ and In+. These uncertainties approach recent estimates of the limits of precision of currently proposed optical atomic clocks. We discuss directions of future theoretical developments for reducing clock uncertainties resulting from blackbody radiation shifts.
介绍了对光学原子钟黑体辐射（BBR）位移的近期理论计算的综述。我们总结了以前通过相对论全阶单双方法获得的单价离子的结果，其中包括对狄拉克-福克波函数的所有单激发和双激发，以及所有阶次的微扰理论。然后介绍了一种用于精确计算二价原子 BBR 位移的新方法。该方法结合了相对论全阶方法和组态相互作用方法，可准确处理具有两个价电子的原子中的相关修正。对 B+、Al+和 In+的 BBR 位移的计算使我们能够降低这些原子在室温下测量的时钟跃迁频率的当前分数不确定度：对于 Al+为 4×10-19，对于 B+和 In+为 10-18。这些不确定性接近目前提出的光学原子钟精度极限的最新估计。我们讨论了减少由于黑体辐射位移引起的时钟不确定性的未来理论发展方向。
