IQIM Postdoctoral and Graduate Student Seminar
Abstract: We perform precise studies of two-and three-body interactions near an intermediate-strength Feshbach resonance in potassium-39 at 33.5820(14) G. Precise measurement of dimer binding energies enables the construction of a complete two-body coupled-channel model for determination of the scattering lengths with an unprecedented low uncertainty. Utilizing such an accurate scattering length map, we unambiguously locate four distinct features in the Efimov three-body structure. Meticulous characterization of and correction for finite temperature effects ensure high accuracy on the measurements of these features at large-magnitude scattering lengths. We report the ground Efimov resonance location to be at −14.05(17) times the van der Waals length r_vdW, significantly deviating from the value of −9.7r_vdW predicted by van der Waals universality . While three of these features form ratios that obey the Efimov universal scaling to within 10% .
Attend the talk at: https://caltech.zoom.us/j/97280252054
Talks will also be posted on IQIM's YouTube page https://www.youtube.com/channel/UC5TeDDv2O31r8B47iEUEgNQ