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arXiv 1402.4335cond-mat.quant-gasphysics.atm-clusquant-ph
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螺旋几何中偶极粒子经典晶体的形成

Formation of classical crystals of dipolar particles in a helical geometry

J. K. Pedersen, D. V. Fedorov, A. S. Jensen, N. T. Zinner

摘要:

我们考虑晶体形成的粒子与偶极子-偶极子相互作用,被限制在一个一维的螺旋几何形状与他们的偶极矩取向沿对称轴的限制螺旋。稳定的经典的最低能量配置被发现是链结构的一个大范围的间距半径比相对较低的密度的偶极子和一个中等的粒子总数。经典的简正模谱支持链的解释,通过结构和不同的简并依赖于每转偶极子的数量离散。较大的偶极总数导致偶极链彼此靠近的集群化。这意味着局部密度的变化和两个长度尺度的出现,一个是集群大小,一个是集群间的距离。从每转三个偶极子开始,这意味着初始周期性的打破,以形成两个链靠近在一起的集群,第三个链从集群中移除。这是由链内和链外相互作用之间的竞争驱动的,或者是系统中的并排排斥和首尾吸引。声音的声速沿着链传播。尽管取决于几何形状,但它与链的数量无关。

英文摘要:

We consider crystal formation of particles with dipole-dipole interactions that are confined to move in a one-dimensional helical geometry with their dipole moments oriented along the symmetry axis of the confining helix. The stable classical lowest energy configurations are found to be chain structures for a large range of pitch-to-radius ratios for relatively low density of dipoles and a moderate total number of particles. The classical normal mode spectra support the chain interpretation both through structure and the distinct degeneracies depending discretely on the number of dipoles per revolution. A larger total number of dipoles leads to a clusterization where the dipolar chains move closer to each other. This implies a change in the local density and the emergence of two length scales, one for the cluster size and one for the inter-cluster distance along the helix. Starting from three dipoles per revolution, this implies a breaking of the initial periodicity to form a cluster of two chains close together and a third chain removed from the cluster. This is driven by the competition between in-chain and out-of-chain interactions, or alternatively the side-by-side repulsion and the head-to-tail attraction in the system. The speed of sound propagates along the chains. It is independent of the number of chains although depending on geometry.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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