论文标题
控制有和没有宏观场的小簇的形状
Controlling the shape of small clusters with and without macroscopic fields
论文作者
论文摘要
尽管在过去几十年中了解纳米群体的形成和动态方面取得了重大进展，但仍缺乏控制其形状的理论基础。我们研究了将波动的几个粒子簇驱动到任意目标形状的策略，无论有或没有外部场。这个问题被重新验证为第一个通道问题，该问题是在数值上解决的，并在高温膨胀中进行了讨论。没有场，大型低能目标形状将在最短时间内达到最佳温度。然后，我们计算设置外部场的最佳方法，以最大程度地减少到达目标的时间，从而在增加簇大小或降低温度时会增加时间增长。这种增益可以改变最佳温度，甚至可以创建一个。我们的结果可能适用于平衡处的原子簇，以及在热或电泳下的胶体或纳米颗粒簇。
Despite major advances in the understanding of the formation and dynamics of nano-clusters in the past decades, theoretical bases for the control of their shape are still lacking. We investigate strategies for driving fluctuating few-particle clusters to an arbitrary target shape in minimum time with or without an external field. This question is recast into a first passage problem, solved numerically, and discussed within a high temperature expansion. Without field, large-enough low-energy target shapes exhibit an optimal temperature at which they are reached in minimum time. We then compute the optimal way to set an external field to minimize the time to reach the target, leading to a gain of time that grows when increasing cluster size or decreasing temperature. This gain can shift the optimal temperature or even create one. Our results could apply to clusters of atoms at equilibrium, and colloidal or nanoparticle clusters under thermo- or electrophoresis.
