Ultracold charged atom-dimer collisions: State-selective charge exchange and three-body recombination

Based on an accurate determination of the potential energy surfaces of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msubsup><a:mi>Rb</a:mi><a:mn>3</a:mn><a:mo>+</a:mo></a:msubsup></a:math> correlated to its first asymptotic limit <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:msup><b:mrow><b:mi>Rb</b:mi></b:mrow><b:mo>+</b:mo></b:msup><b:mo>+</b:mo><b:mi>Rb</b:mi><b:mrow><b:mo>(</b:mo><b:mn>5</b:mn><b:mi>s</b:mi><b:mo>)</b:mo></b:mrow><b:mo>+</b:mo><b:mi>Rb</b:mi><b:mrow><b:mo>(</b:mo><b:mn>5</b:mn><b:mi>s</b:mi><b:mo>)</b:mo></b:mrow></b:mrow></b:math>, we identify the presence of intersections of a pair of singlet and triplet surfaces over all interparticle distances, leading to Jahn-Teller (JT) couplings. We elaborate scenarios for charge exchange between ultracold charged atom-dimer complex (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mi>Rb</c:mi><c:mo>+</c:mo><c:msubsup><c:mi>Rb</c:mi><c:mn>2</c:mn><c:mo>+</c:mo></c:msubsup></c:mrow></c:math> or <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:msup><d:mrow><d:mi>Rb</d:mi></d:mrow><d:mo>+</d:mo></d:msup><d:mo>+</d:mo><d:msub><d:mi>Rb</d:mi><d:mn>2</d:mn></d:msub></d:mrow></d:math>), predicting a strong selectivity on the preparation of the initial state of the dimer. We also demonstrate that the JT couplings must drive the three-body recombination (TBR) of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:msup><e:mrow><e:mi>Rb</e:mi></e:mrow><e:mo>+</e:mo></e:msup></e:math>, Rb, and Rb at ultracold energies. Using the current analysis, we provide a consistent picture of the TBR experiments performed in ion-atom hybrid Rb samples. We also demonstrate the presence of JT coupling as a general phenomenon in the singly charged homonuclear alkali triatomic systems. Published by the American Physical Society 2024