论文标题
在超级流体过渡中统一费米子的隧道运输
Tunneling transport of unitary fermions across the superfluid transition
论文作者
论文摘要
我们研究了在超级流体相变的fermi气体在跨隧道连接处的直流电流（DC）驱动的响应。随着超流体临界温度从下面穿过，我们观察到从高度非线性到欧姆传导特征的演变，与对凝集耗尽诱导的Josephson DC电流的临界分解有关。此外，我们揭示了对电阻电流的较大且优势的异常贡献，该贡献在最低的温度下达到了最大值，这是由冷凝水和Phononic Bogoliubov-Anderson激励之间的隧道耦合所促进的。增加温度，而超级电流的零标则标志着正常相的过渡，电导率下降大大下降，但仍比正常的，不相关的费米气体隧穿通过同一交界处大得多。我们将这种增强的运输归因于声音模式的不一致的隧道，这些隧道在单位性的未配对费米子的碰撞流体动力流体中仍然微弱地阻尼。
We investigate the transport of a Fermi gas with unitarity-limited interactions across the superfluid phase transition, probing its response to a direct current (dc) drive through a tunnel junction. As the superfluid critical temperature is crossed from below, we observe the evolution from a highly nonlinear to an Ohmic conduction characteristics, associated with the critical breakdown of the Josephson dc current induced by pair condensate depletion. Moreover, we reveal a large and dominant anomalous contribution to resistive currents, which reaches its maximum at the lowest attained temperature, fostered by the tunnel coupling between the condensate and phononic Bogoliubov-Anderson excitations. Increasing the temperature, while the zeroing of supercurrents marks the transition to the normal phase, the conductance drops considerably but remains much larger than that of a normal, uncorrelated Fermi gas tunneling through the same junction. We attribute such enhanced transport to incoherent tunneling of sound modes, which remain weakly damped in the collisional hydrodynamic fluid of unpaired fermions at unitarity.
