Probing the many-body physics via measurement of the closed-channel fraction in a <sup>6</sup>Li superfluid
ORAL
Abstract
Atomic Fermi gases provide an ideal platform for studying the pairing and superfluid physics, utilizing a Feshbach resonance between closed channel molecular states and open channel scattering states. The closed-channel fraction Z contains important many-body interacting effects. Here we probe the many-body physics of interacting Fermi gases of 6Li by measuring Z in the entire system. We have observed a significant departure from two-body physics. Away from
the deep BEC regime, the fraction Z is sensitive to the Fermi temperature TF. In particular, our data show Z∝ √TF at unitarity, in good agreement with theory. Further more, we have found a progressive departure of our measured Z value from theory as the system enters the BCS regime, calling for further investigation in both theory and experiment.
the deep BEC regime, the fraction Z is sensitive to the Fermi temperature TF. In particular, our data show Z∝ √TF at unitarity, in good agreement with theory. Further more, we have found a progressive departure of our measured Z value from theory as the system enters the BCS regime, calling for further investigation in both theory and experiment.
*This work is supported by the National Key R&D Program of China (under Grant No. 2018YFA0306501), the NSFC of China (under Grant No. 11425417 and No. 11774309), the CAS, and the Fundamental Research Funds for the Central Universities (under Grant No. WK2340000081), NSF of Zhejiang Province of China (Grant No. LZ13A040001), and NSF-DMR-MRSEC 1420709.
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Presenters
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Xing-Can Yao
- Department of Modern Physics, University of Science and Technology of China