Trapping of Topological-Structural Defects in Coulomb Crystals
Trapping of Topological-Structural Defects in Coulomb Crystals
复制标题
DOI：
10.1103/physrevlett.110.133004
复制
发表时间：
2013-03-28
影响因子：
8.6
通讯作者：
Reznik, B.
中科院分区：
文献类型：
--
作者：
Mielenz, M.;Brox, J.;Reznik, B.
我们从实验和理论上研究了在线性射频阱中从激光冷却的云到库仑晶体的过渡过程中形成的结构缺陷。我们证明了预测的拓扑缺陷（“扭结”）在纯二维晶体中的创建，也发现扭结显示新的动力学特征的参数没有考虑过的制度。扭结总是观察到的陷阱的中心，显示出一个大的非线性局部激发，其发生的概率饱和在类似于0.5。模拟结果表明，由于扭结的扩展到三维空间，扭结的内部振动模式具有很强的非谐性。因此，离散扭结所经历的周期性Peierls-Nabarro势成为全局限制势，能够在晶体中心捕获一个冷却缺陷。DOI：10.1103/PhysRevLett.110.133004
We study experimentally and theoretically structural defects which are formed during the transition from a laser cooled cloud to a Coulomb crystal, consisting of tens of ions in a linear radio frequency trap. We demonstrate the creation of predicted topological defects("kinks'') in purely two-dimensional crystals and also find kinks which show novel dynamical features in a regime of parameters not considered before. The kinks are always observed at the center of the trap, showing a large nonlinear localized excitation, and the probability of their occurrence saturates at similar to 0.5. Simulations reveal a strong anharmonicity of the kink's internal mode of vibration, due to the kink's extension into three dimensions. As a consequence, the periodic Peierls-Nabarro potential experienced by a discrete kink becomes a globally confining potential, capable of trapping one cooled defect at the center of the crystal. DOI: 10.1103/PhysRevLett.110.133004