论文标题
移动杂质探测二维超氟相过渡
Mobile impurity probing a two-dimensional superfluid phase transition
论文作者
论文摘要
将原子尺寸的量子系统用作高度敏感的测量设备代表了一个令人兴奋且快速增长的研究领域。在这里，我们探讨了由移动杂质与二维费米子超级流体相互作用的准杂质形成的属性。由于这增加了费米气体的可压缩性，因此证明了准粒子的能量可以通过超流晶搭配而降低，从而使杂质更容易扰动其周围环境。我们证明，超氟从根本上不连续到二维系统的正常相变的性质，导致围绕临界温度围绕临界温度的准粒子能量迅速增加。这种增加的幅度表现出非单调的行为与配对强度的函数在交叉区域中具有相当大的最大值的函数，在该区域中，库珀对的空间延伸与颗粒间距相当。 由于当前的实验技术可以测量准粒子能量，因此我们的结果说明了与环境纠缠的杂质如何成为非平凡热和量子相关性的有用探针。
The use of atomically sized quantum systems as highly sensitive measuring devices represents an exciting and quickly growing research field. Here, we explore the properties of a quasiparticle formed by a mobile impurity interacting with a two-dimensional fermionic superfluid. The energy of the quasiparticle is shown to be lowered by superfluid pairing as this increases the compressibility of the Fermi gas, thereby making it easier for the impurity to perturb its surroundings. We demonstrate that the fundamentally discontinuous nature of the superfluid to normal phase transition of a two-dimensional system, leads to a rapid increase in the quasiparticle energy around the critical temperature. The magnitude of this increase exhibits a nonmonotonic behavior as a function of the pairing strength with a sizable maximum in the cross-over region, where the spatial extend of the Cooper pairs is comparable to the interparticle spacing. Since the quasiparticle energy is measurable with present experimental techniques, our results illustrate how impurities entangled with their environment can serve as useful probes for non-trivial thermal and quantum correlations.
