In this work, we study the nonlinear Josephson dynamics of Fermi superfluids in the crossover from Bardeen–Cooper–Schrieffer (BCS) superfluid to a molecular Bose-Einstein condensate (BEC) in a double-well potential. Under a two-mode approximation, we derive a full two-mode (fTM) model including all interaction energy terms. By solving the fTM model numerically, we study the zero-phase and [Formula: see text]-phase modes of Josephson oscillations in the BCS–BEC crossover. We find that in the strongly interacting regime the cross interaction terms not appearing in the two-mode model cannot be easily ignored. The cross interactions can alter the behaviors of Josephson dynamics substantially, and interestingly the alterations for the zero-phase and [Formula: see text]-phase modes are just opposite.

中文翻译：

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双井势中强相互作用超流体费米气体的约瑟夫森动力学

在这项工作中，我们研究了费米超流体在双阱势中从 Bardeen-Cooper-Schrieffer (BCS) 超流体到分子玻色-爱因斯坦凝聚体 (BEC) 的交叉中的非线性约瑟夫森动力学。在双模近似下，我们推导出一个包含所有相互作用能量项的完整双模 (fTM) 模型。通过数值求解 fTM 模型，我们研究了 BCS-BEC 交叉中约瑟夫森振荡的零相位和 [公式：见文本] 相位模式。我们发现，在强相互作用机制中，不能轻易忽略双模模型中未出现的交叉相互作用项。交叉相互作用可以显着改变约瑟夫森动力学的行为，有趣的是零相位和[公式：见文本]相位模式的变化正好相反。