Caltech Logo

IQIM Postdoctoral and Graduate Student Seminar

Friday, December 4, 2020
11:00am to 12:00pm
Add to Cal
Online Event
Precise Calibrations of Few-Body Physics in Potassium-39
Xin Xie, IQIM Postdoctoral Scholar, Endres Group,

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 [1]. While three of these features form ratios that obey the Efimov universal scaling to within 10% [2].

[1]https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.233402

[2]https://journals.aps.org/prl/accepted/94071Yb5H8819f8421972b1289f4d229daf32da51

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

For more information, please contact Marcia Brown by phone at 626-395-4013 or by email at marciab@caltech.edu.