Institut für Theoretische Physik, Albert-Einstein Allee 11, Universität Ulm, D-89069 Ulm, Germany.
Phys Rev Lett. 2010 Aug 13;105(7):075701. doi: 10.1103/PhysRevLett.105.075701. Epub 2010 Aug 11.
The nonequilibrium dynamics of an ion chain in a highly anisotropic trap is studied when the transverse trap frequency is quenched across the value at which the chain undergoes a continuous phase transition from a linear to a zigzag structure. Within Landau theory, an equation for the order parameter, corresponding to the transverse size of the zigzag structure, is determined when the vibrational motion is damped via laser cooling. The number of structural defects produced during a linear quench of the transverse trapping frequency is predicted and verified numerically. It is shown to obey the scaling predicted by the Kibble-Zurek mechanism, when extended to take into account the spatial inhomogeneities of the ion chain in a linear Paul trap.
当横向陷阱频率在使链经历从线性到之字形结构的连续相变的临界值以下被猝灭时，研究了高度各向异性陷阱中离子链的非平衡动力学。在朗道理论中，当通过激光冷却阻尼振动运动时，确定了对应于之字形结构的横向尺寸的序参量方程。预测并通过数值验证了在横向俘获频率的线性猝灭过程中产生的结构缺陷的数量。当将其扩展到考虑线性 Paul 陷阱中离子链的空间非均匀性时，它被证明符合 Kibble-Zurek 机制的预测。
