We theoretically investigate quantum conductance across a point contact between two strongly-interacting ultracold Fermi gases. We evaluate the tunneling current, taking into account pairing fluctuations in the Fermi gases within the framework of a combined strong-coupling T -matrix approximation with the Schwinger-Keldysh non-equilibrium formalism. We show that quasi-particle conductance is gradually suppressed, as one passes through the BCS–BEC crossover region from the weak-coupling side. On the other hand, with increasing the strength of a pairing interaction, the fluctuation-pair conductance is found to remarkably increase in the crossover region, which is followed by the suppression in the strong-coupling regime.

中文翻译：

---

超冷费米气体中量子输运的强耦合效应

我们从理论上研究了两种强相互作用的超冷费米气体之间点接触的量子电导。我们评估隧道电流，考虑到费米气体在结合强耦合 T 矩阵近似与 Schwinger-Keldysh 非平衡形式主义的框架内的配对波动。我们表明，随着从弱耦合侧穿过 BCS-BEC 交叉区域，准粒子电导逐渐被抑制。另一方面，随着配对相互作用强度的增加，发现波动对电导在交叉区域显着增加，随后在强耦合区域受到抑制。