Finite-temperature p-wave contact and loss rate of Femi gases

报告题目:Finite-temperature p-wave contact and loss rate of Femi gases

报告人:严杨千 助理教授(香港中文大学)




Motivated by the experimental realization of single-component degenerate Fermi gases of polar ground state KRb molecules with intrinsic two-body losses [L. De Marco, G. Valtolina, K. Matsuda, W. G. Tobias, J. P. Covey, and J. Ye, A degenerate Fermi gas of polar molecules], we study the finite-temperature loss rate of single-component Fermi gases with weak interactions. First, we establish a relationship between the two-body loss rate and the p-wave contact. Second, we evaluate the contact of the homogeneous system in the low-temperature regime using p-wave Fermi liquid theory and in the high-temperature regime using the second-order virial expansion. Third, conjecturing that there are no phase transitions between the two temperature regimes, we smoothly interpolate the results to intermediate temperatures.

It is found that the contact is constant at temperatures close to zero and increases first quadratically with increasing temperature and finally---in agreement with the Bethe-Wigner threshold law---linearly at high temperatures. Fourth, applying the local-density approximation, we obtain the loss rate for the harmonically trapped system, reproducing the experimental KRb loss measurements within a unified theoretical framework over a wide temperature regime without fitting parameters. Our results for the contact are not only applicable to molecular p-wave gases but also to atomic single-component Fermi gases, such as K and Li.


严杨千本科就读于中科大,并在华盛顿州立大学取得博士学位,师从D Blume教授,并专注于超冷原子分子气体与少体物理的研究工作。博士毕业后在普度大学物理与天文系担任博士后周琦教授组任副研究员。2021年8月在香港中文大学物理系任助理教授。