Temperature-Dependent Periodicity of the Persistent Current in Strongly Interacting Systems
Temperature-Dependent Periodicity of the Persistent Current in Strongly Interacting Systems
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DOI：
10.1103/physrevlett.128.096801
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发表时间：
2022-03-04
影响因子：
8.6
通讯作者：
Averin, Dmitri, V
中科院分区：
文献类型：
--
作者：
Patu, Ovidiu, I;Averin, Dmitri, V
封闭磁通量的小隔离环中的持续电流是在没有外部激励的情况下平衡循环的电流。虽然最初是在超导和普通金属中进行研究，但最近在超冷气体中产生的原子持续电流激发了新一波的理论研究。然而，我们对相互作用系统中持续电流的理解还远未完成，特别是在有限温度下。在这里，我们考虑费米子一维哈伯德模型，并表明在强相互作用极限下，电流可以根据温度改变其通量周期和符号（抗磁性或顺磁性），这些特征无法在单粒子或卢廷格液体技术中解释。此外，电流的大小除了根据系统的极化呈现不同的衰减率之外，还可能随着温度的增加而增加。我们的工作强调了传统近似技术所忽略的强相互作用多组分系统的特性，但对于解释超冷气体中持续电流的实验非常重要。
The persistent current in small isolated rings enclosing magnetic flux is the current circulating in equilibrium in the absence of an external excitation. While initially studied in superconducting and normal metals, recently, atomic persistent currents have been generated in ultracold gases spurring a new wave of theoretical investigations. Nevertheless, our understanding of the persistent currents in interacting systems is far from complete, especially at finite temperatures. Here we consider the fermionic one-dimensional Hubbard model and show that in the strong-interacting limit, the current can change its flux period and sign (diamagnetic or paramagnetic) as a function of temperature, features that cannot be explained within the single-particle or Luttinger liquid techniques. Also, the magnitude of the current can counterintuitively increase with temperature, in addition to presenting different rates of decay depending on the polarization of the system. Our work highlights the properties of the strongly interacting multicomponent systems that are missed by conventional approximation techniques, but can be important for the interpretation of experiments on persistent currents in ultracold gases.