Hannover 2010 – scientific programme

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A: Fachverband Atomphysik

A 19: Ultra-Cold Plasmas and Rydberg System

A 19.1: Invited Talk

Thursday, March 11, 2010, 10:30–11:00, B 302

Bound by reflection: Binding mechanisms of ultralong range Rydberg molecules — •Weibin Li — Max Planck Institute for the Physics of Complex Systems, Dresden, Germany

Quantum reflection, as a pure wave phenomenon, involves the reflection of a particle, which would classically be transmitted. For highly excited atoms it is found that this effect can lead to molecular bound states at extremely long range. Recent experiments have provided evidence for the existence of such ultralong-range molecules, arising entirely from low-energy scattering between a Rydberg electron and a nearby ground state atom. Here, I will report on recent calculations of the molecular structure, that account for such collisions in a non-perturbative way. A broad range of molecular lines are identified, and shown to originate from two different sources: a Rydberg trimer formed in a single-photon association and a series of excited dimer states that arise from, thus far, an unexplored mechanism based on internal quantum reflection at a steep potential drop caused by a shape resonance in electron-atom scattering. The theory shows good agreement with previous experiments and allows to assign the majority of molecular lines observed in recently measured spectra of ultralong-range Rydberg molecules.