近日，波兰国家核研究中心的Pawel Zin与波兰科学院物理研究所的Mariusz Gajda合作并取得一项新进展。他们对三维到一维交叉处的偶极液滴进行了研究。相关研究成果已于2024年12月23日在国际知名学术期刊《物理评论A》上发表。

该研究团队研究了在两个方向上受到强烈约束，且偶极子沿系统长轴排列的细长均匀玻色气体的能量，考虑了超出平均场近似的修正。当偶极相互作用达到其临界强度时，平均场方法预测系统将会不稳定。然而，与自由空间情况类似，超出平均场效应显著改变了系统的基态，导致形成了一种自束缚的原子云，即量子液滴。

这项分析表明，在准一维区域中，除了约束诱导的平均场能量偏移外，超出平均场的能量贡献与密度的三次方（约等于n³）成正比。因此，这可以被解释为一种有效的三体排斥力，它使气体稳定，防止坍塌，并导致有限密度的解。研究人员还表明，在谐振约束下，这种效应对于强细长偶极液滴的束缚起着至关重要的作用。

附：英文原文

Title: Dipolar droplets at the crossover from three dimensions to one dimension

Author: Maciej Pylak^1,*, Mariusz Gajda², and Pawel Zin¹

Issue&Volume: 2024-12-23

Abstract: We investigate beyond-mean-field corrections to the energy of an elongated homogeneous Bose gas strongly confined in two directions, with dipoles aligned along the long axis of the system. When the dipolar interaction reaches its critical strength, the mean-field approach predicts instability. However, similar to the free-space case, beyond-mean-field effects significantly alter the ground state of the system, leading to the formation of a self-bound atomic cloud known as a quantum droplet. Our analysis demonstrates that the beyond-mean-field contribution to the energy in the quasi-one-dimensional region, in addition to the confinement-induced shift of the mean-field energy, is proportional to the third power of the density approximately equal to n³. Therefore, it can be interpreted as an effective three-body repulsion that stabilizes the gas, preventing collapse and leading to a finite-density solution. We also show that the same effect plays a crucial role in the binding of strongly elongated dipolar droplets under harmonic confinement.

DOI: 10.1103/PhysRevA.110.063322

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.063322