A Jahn–Teller analysis of K3 and Rb3 in the electronic states 12E′ and 12E″

Homo- and heteronuclear alkali metal trimers formed on helium nanodroplets. Part II. Femtosecond spectroscopy and spectra assignments

“…As an example, the doublet ground state have potential of Rb 3 (1 2 E ) has a formation energy of about 5321 cm −1 as compared to 939 cm −1 for the 1 4 A 2 lowest quartet state. 34,48 Thus-formed trimers immediately thermalize to the nanodroplet equilibrium temperature (370 mK) such that only the vibrational ground state (v = 0) and a few rotational states are populated. Thus, helium nanodroplet isolation (HENDI) is an ideal method for species and state preparation to perform single quantum channel experiments.…”

“…In the case of the homonuclear trimers K 3 and Rb 3 we fall back to the ab initio results of our previous articles on the quartet 34 and doublet 48 states. For our approach to the mixed trimers K 2 Rb and KRb 2 we refer the potential surfaces and the corresponding energy levels of Paper I.…”

“…The article is organized as follows: After a short description of the apparatus the experimental results are presented and data analysis is exemplified for Rb 3 . This is followed by a theoretical part summarizing the findings of our previous ab initio calculations on these systems 34,35,48 and makes extensive use of the data provided in the closely connected Ref. 59, which is referred to as Paper I throughout this article.…”

“…However, with the advances in computational power and techniques, PES for homo-and heteronuclear alkali trimers involving potassium, rubidium and cesium have recently been determined by several groups. 12,34,36,48,49 Besides, alkali trimers in quartet states are particularly well suited for studying nonadditive three-body interaction terms, which represent significant contributions to the binding energy. 30,50 Recent advances in forming ultracold molecules by photoor magneto-association through Feshbach resonances using trapped samples of ultracold atoms has stimulated increasing demand for accurate PES of three-atomic systems.…”

“…Besides the mentioned spin-orbit couplings the Jahn-Teller (JT) effect, specifically the problem of E⊗e vibronic coupling, has been a matter of high interest and continuous research. 34,48 The calculation of accurate potential energy surfaces (PES) for trimers formed of the heavy alkali elements is computationally quite demanding. However, with the advances in computational power and techniques, PES for homo-and heteronuclear alkali trimers involving potassium, rubidium and cesium have recently been determined by several groups.…”