论文标题
由于流体金属中电子离域化引起的原子扩散的增强
Enhancement of Atomic Diffusion due to Electron Delocalization in Fluid Metals
论文作者
论文摘要
我们提出了一种在流体金属中莫特金属绝缘体过渡附近的原子自扩散的一般理论。从莫特绝缘阶段减少电子相关性后，电子的离域化会导致有吸引力的原子间相互作用增加，这有望引入额外的摩擦，因此降低了原子的扩散率。然而，我们的量子分子动力学模拟发现了新兴的吸引力引起的扩散系数的有趣增强。我们表明，这种违反直觉现象是由于排斥核的减少以及通过热波动对吸引人的尾巴的抑制而引起的。基于摩尔斯电位的标准液体模型上的查普曼 - 恩斯科理论和经典分子动力学模拟了所提出的方案。我们的工作不仅提供了吸引易吸引力的扩散增强的一般机制，而且还为电子相关性对原子动力学的非平凡影响提供了新的光。
We present a general theory of atomic self-diffusion in the vicinity of a Mott metal-insulator transition in fluid metals. Upon decreasing the electron correlation from the Mott insulating phase, the delocalization of electrons gives rise to an increasing attractive interatomic interaction, which is expected to introduce an additional friction, hence reducing the atomic diffusivity. Yet, our quantum molecular dynamics simulations find an intriguing enhancement of the diffusion coefficient induced by the emerging attractive force. We show that this counterintuitive phenomenon results from the reduction of the repulsive core and the suppression of the attractive tail by thermal fluctuations. The proposed scenario is corroborated by the Chapman-Enskog theory and classical molecular dynamics simulations on a standard liquid model based on the Morse potential. Our work not only provides a general mechanism of the attraction-facilitated diffusion enhancement in simple liquids, but also sheds new lights on the nontrivial effects of electron correlation on atomic dynamics.
