2011/11/07 by Cheng Chin, Chin, Cheng
Physics and Astronomy · #Advanced Chemical Physics Studies #Atomic Physics (physics.atom-ph) #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas) #Quantum, superfluid, helium dynamics
paper · pdf · doi:10.48550/arxiv.1111.1484
openalex publication_date 2011/11/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recent cold atom experiments report a surprising universal scaling of the first Efimov resonance position a-1 by the two-body van der Waals length rvdW. The ratio C=-a-1/rvdW=8.5~9.5 for identical particles appears to be a constant regardless of the atomic spin configuration, the Feshbach resonance employed to tune the scattering length, and even the atomic species, with K-39 being the only exception. This result indicates that the Efimov energy structure is insensitive to the details of the short range potential. We suggest that the universality results from the quantum reflection of the Efimov wavefunciton by the short-range molecular potential. Assuming Born-Oppenheimer approximation and strong quantum reflection, we obtain an analytic result of C=9.475... for three identical particles. We suspect the exceptional case of K-39 is a result of resonant coupling between the Efimov state and a short-range molecular state.