近日，西班牙马德里自治大学的Francesca Maria Marchetti及其研究团队与澳大利亚莫纳什大学的Jesper Levinsen等人合作并取得一项新进展。经过不懈努力，他们对双层几何结构中具有偶极费米子的多重极化子准粒子进行研究。相关研究成果已于2024年3月25日在国际知名学术期刊《物理评论A》上发表。

该研究团队深入探讨了双层几何结构中偶极费米子的费米极化子问题。在这一结构中，一层中的单个偶极粒子与另一层费米海中的偶极费米子产生相互作用。通过精确计算极化子谱，研究人员发现，随着层间距离的逐渐减小，出现了一系列有吸引力的分支。这些分支与层间偶极相互作用强度增强时产生的一系列束缚双偶极态密切相关。进一步观察极化子分支的轨道角动量分量，研究人员发现，当气体密度、层间距离等系统参数发生变化时，轨道特性也随之改变。

此外，他们还探索了费米子密度超过某临界值时，最低能量的二体束缚态是否会自发获得有限质心动量的可能性，并确定了表征配对性的主导轨道角动量。最后，他们建议，在实验中使用辅助层的隧穿速率以及进入辅助层的隧穿速率，作为研究杂质谱函数的有效探针。

附：英文原文

Title: Multiple polaron quasiparticles with dipolar fermions in a bilayer geometry

Author: Antonio Tiene, Andrés Tamargo Bracho, Meera M. Parish, Jesper Levinsen, Francesca Maria Marchetti

Issue&Volume: 2024/03/25

Abstract: We study the Fermi polaron problem with dipolar fermions in a bilayer geometry, where a single dipolar particle in one layer interacts with a Fermi sea of dipolar fermions in the other layer. By evaluating the polaron spectrum, we obtain the appearance of a series of attractive branches when the distance between the layers diminishes. We relate these to the appearance of a series of bound two-dipole states when the interlayer dipolar interaction strength increases. By inspecting the orbital angular-momentum component of the polaron branches, we observe an interchange of orbital character when system parameters such as the gas density or the interlayer distance are varied. Furthermore, we study the possibility that the lowest energy two-body bound state spontaneously acquires a finite center-of-mass momentum when the density of fermions exceeds a critical value, and we determine the dominating orbital angular momenta that characterize the pairing. Finally, we propose to use the tunneling rate from and into an auxiliary layer as an experimental probe of the impurity spectral function.

DOI: 10.1103/PhysRevA.109.033318

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.033318