QOLS Group, Department of Physics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Nat Commun. 2013;4:2571. doi: 10.1038/ncomms3571.
Laser-cooled atomic ions form ordered structures in radiofrequency ion traps and in Penning traps. Here we demonstrate in a Penning trap the creation and manipulation of a wide variety of ion Coulomb crystals formed from small numbers of ions. The configuration can be changed from a linear string, through intermediate geometries, to a planar structure. The transition from a linear string to a zigzag geometry is observed for the first time in a Penning trap. The conformations of the crystals are set by the applied trap potential and the laser parameters, and agree with simulations. These simulations indicate that the rotation frequency of a small crystal is mainly determined by the laser parameters, independent of the number of ions and the axial confinement strength. This system has potential applications for quantum simulation, quantum information processing and tests of fundamental physics models from quantum field theory to cosmology.
激光冷却的原子离子在射频离子阱和彭宁阱中形成有序结构。在这里，我们在彭宁阱中演示了由少量离子形成的各种离子库仑晶体的产生和操纵。该配置可以从线性字符串，通过中间几何形状，改变为平面结构。在彭宁阱中首次观察到从线性字符串到锯齿形几何形状的转变。晶体的构象由所施加的阱势和激光参数确定，并与模拟结果一致。这些模拟表明，小晶体的旋转频率主要由激光参数决定，与离子数量和轴向约束强度无关。该系统具有用于量子模拟、量子信息处理和从量子场论到宇宙学的基本物理模型测试的潜在应用。
