| Autor: |
Li, Xi, Wang, Shuai, Luo, Xiang, Zhou, Yu-Yang, Xie, Ke, Shen, Hong-Chi, Nie, Yu-Zhao, Chen, Qijin, Hu, Hui, Chen, Yu-Ao, Yao, Xing-Can, Pan, Jian-Wei |
| Rok vydání: |
2023 |
| Předmět: |
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| Druh dokumentu: |
Working Paper |
| Popis: |
The nature of pseudogap lies at the heart of strongly-interacting superconductivity and superfluidity. With known pairing interactions, unitary Fermi gases provide an ideal testbed to verify whether a pseudogap can arise from many-body pairing. Here we report the observation of the long-sought pair-fluctuation-driven pseudogap in homogeneous unitary Fermi gases of lithium-6 atoms, by precisely measuring the spectral function through momentum-resolved microwave spectroscopy without the serious effects of final-state effect. We find a large pseudogap above the superfluid transition. The inverse pair lifetime exhibits a thermally-activated exponential behavior, uncovering the microscopic virtual pair breaking and recombination mechanism. The obtained large, T-independent single-particle scattering rate is comparable with that set by the Planckian limit. Our findings quantitatively characterize the pseudogap in strongly-interacting Fermi gases, highlighting the role of preformed pairing as a precursor to superfluidity. |
| Databáze: |
arXiv |
| Externí odkaz: |
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