A molecular dynamics simulation study on trapping ions in a nanoscale Paul trap
A molecular dynamics simulation study on trapping ions in a nanoscale Paul trap
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DOI：
10.1088/0957-4484/19/19/195702
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发表时间：
2008-05-14
期刊：
影响因子：
3.5
通讯作者：
Krstic, Predrag S.
中科院分区：
文献类型：
--
作者：
Zhao, Xiongce;Krstic, Predrag S.
我们通过分子动力学模拟发现，在真空和水环境中，当施加适当的交直流电场时，低能离子都可以被有效地捕获在纳米级的Paul陷阱中。以带负电荷的氯离子为例，我们证明了捕获的离子围绕纳米陷阱中心振荡，其幅度依赖于系统参数和外加电压。要在纳秒内成功捕获离子，需要数百毫伏范围内的GHz频率的电偏置。这种振荡在水环境中被抑制，但水分子的极化需要施加更高的电压偏置来达到更好的捕获稳定性。沿陷阱轴线施加附加的直流驱动磁场可以有效地将离子驱离陷阱中心和陷阱外，从而为使用嵌入的探针研究DNA和其他带电分子打开了可能性，同时实现了对它们在陷阱中的移位和定位的完全控制。
We found by molecular dynamics simulations that a low energy ion can be trapped effectively in a nanoscale Paul trap in both vacuum and aqueous environments when appropriate AC/DC electric fields are applied to the system. Using the negatively charged chlorine ion as an example, we show that the trapped ion oscillates around the center of the nanotrap with an amplitude dependent on the parameters of the system and applied voltages. Successful trapping of the ion within nanoseconds requires an electric bias of GHz frequency, in the range of hundreds of mV. The oscillations are damped in the aqueous environment, but polarization of water molecules requires the application of a higher voltage bias to reach improved stability of the trapping. Application of a supplemental DC driving field along the trap axis can effectively drive the ion off the trap center and out of the trap, opening up the possibility of studying DNA and other charged molecules using embedded probes while achieving a full control of their translocation and localization in the trap.