2009/11/04 by Scott E. Pollack, Daniel Dries, Randall G. Hulet · 1 citation
Physics and Astronomy · #cond-mat.quant-gas
paper · pdf · doi:10.1126/science.1182840
16 pages including figures and Supplementary Online Material
arxiv created 2009/11/04 · arxiv updated 2015/05/14
Under certain circumstances, three or more interacting particles may form bound states. While the general few-body problem is not analytically solvable, the so-called Efimov trimers appear for a system of three particles with resonant two-body interactions. The binding energies of these trimers are predicted to be universally connected to each other, independent of the microscopic details of the interaction. By exploiting a Feshbach resonance to widely tune the interactions between trapped ultracold lithium atoms, we find evidence for two universally connected Efimov trimers and their associated four-body bound states. A total of eleven precisely determined three- and four-body features are found in the inelastic loss spectrum. Their relative locations on either side of the resonance agree well with universal theory, while a systematic deviation from universality is found when comparing features across the resonance.