论文标题
用持续的电流探测BCS-BEC跨界
Probing the BCS-BEC crossover with persistent currents
论文作者
论文摘要
我们研究了一个有吸引力的费米气体的持续电流，该电流被限制在紧密的环形环陷阱中，并通过BCS-BEC跨界跨越人造仪表场。在BCS侧的弱景点处，费米子在持续的电流中表现出奇偶校验效应，即它们对量规场的响应是顺磁或磁性的，这取决于环上的对数。在共振和交叉的BEC侧，我们发现地面能量的周期性是人造量规场的函数和平价效应的消失，这表明可以使用持续的电流来推断紧密结合的波音性波音对形成。我们的预测可以通过噪声干涉图在超低原子实验中访问。
We study the persistent currents of an attractive Fermi gas confined in a tightly-confining ring trap and subjected to an artificial gauge field all through the BCS-BEC crossover. At weak attractions, on the BCS side, fermions display a parity effect in the persistent currents, ie their response to the gauge field is paramagnetic or diamagnetic depending on the number of pairs on the ring. At resonance and on the BEC side of the crossover we find a doubling of the periodicity of the ground-state energy as a function of the artificial gauge field and disappearance of the parity effect, indicating that persistent currents can be used to infer the formation of tightly-bound bosonic pairs. Our predictions can be accessed in ultracold atoms experiments through noise interferograms.
