近日，印度普纳大学的Dibyendu Kuiri等取得一项新进展。经过不懈努力，他们通过无序诱导涡旋钉扎控制二元玻色-爱因斯坦凝聚体的涡旋晶格结构。相关研究成果已于2024年6月27日在国际知名学术期刊《物理评论A》上发表。
该研究团队通过数值求解随时间耦合的Gross-Pitaevskii方程，研究了在杂质或无序存在下旋转双组分玻色-爱因斯坦凝聚体(BECs)的涡旋钉扎效应对涡旋晶格结构的影响。研究人员通过改变角频率、组分间相互作用和钉扎势的强度以及周期性钉扎势的晶格常数等条件来研究涡旋晶格结构的跃迁。结果表明，即使单个杂质钉扎电势也能使未钉扎的涡旋晶格结构由三角形变为正方形，或由三角形变为三角形与正方形重叠的结构。
在周期性钉扎电势或光学晶格存在的情况下，研究人员观察到光学晶格从非钉扎涡旋晶格到钉扎涡旋晶格的结构转变。在随机钉扎势或无序存在的情况下，涡旋晶格随着旋转频率的增加，通过产生晶格缺陷、位错和斜位，经过两步过程熔化，类似于观察到的单组分玻色-爱因斯坦凝聚体。然而，对于二元BECs，研究人员发现随着组分间相互作用强度的增加，也会发生两步涡旋晶格熔化。然而，对于二元BECs，研究人员发现随着组分间相互作用强度的增加，也会发生两步涡旋晶格熔化。
附：英文原文
Title: Controlling vortex lattice structure of binary Bose-Einstein condensates via disorder-induced vortex pinning
Author: Dibyendu Kuiri, Thudiyangal Mithun, Bishwajyoti Dey
Issue&Volume: 2024/06/27
Abstract: We study the vortex pinning effect on the vortex lattice structure of the rotating two-component Bose-Einstein condensates (BECs) in the presence of impurities or disorder by numerically solving the time-dependent coupled Gross-Pitaevskii equations. We investigate the transition of the vortex lattice structures by changing conditions such as angular frequency, the strength of the inter-component interaction and pinning potential, and the lattice constant of the periodic pinning potential. We show that even a single impurity pinning potential can change the unpinned vortex lattice structure from triangular to square or from triangular to a structure which is the overlap of triangular and square. In the presence of a periodic pinning potential or optical lattice, we observe the structural transition from the unpinned vortex lattice to the pinned vortex lattice structure of the optical lattice. In the presence of a random pinning potential or disorder, the vortex lattice melts following a two-step process by creation of lattice defects, dislocations, and disclinations, with the increase of rotational frequency, similar to that observed for single-component Bose-Einstein condensates. However, for the binary BECs, we show that the two-step vortex lattice melting also occurs with increasing strength of the intercomponent interaction.
DOI: 10.1103/PhysRevA.109.063333
Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.109.063333
