Mandal Suvendu, Franosch Thomas
Institut für Theoretische Physik, Universität Innsbruck, Technikerstraße 21A, A-6020 Innsbruck, Austria.
Phys Rev Lett. 2017 Feb 10;118(6):065901. doi: 10.1103/PhysRevLett.118.065901. Epub 2017 Feb 6.
We study a strongly interacting dense hard-sphere system confined between two parallel plates by event-driven molecular dynamics simulations to address the fundamental question of the nature of the 3D to 2D crossover. As the fluid becomes more and more confined the dynamics of the transverse and lateral degrees of freedom decouple, which is accompanied by a diverging time scale separating 2D from 3D behavior. Relying on the time-correlation function of the transversal kinetic energy, the scaling behavior and its density dependence is explored. Surprisingly, our simulations reveal that its time dependence becomes purely exponential such that memory effects can be ignored. We rationalize our findings quantitatively in terms of an analytic theory which becomes exact in the limit of strong confinement.
我们通过事件驱动分子动力学模拟研究了限制在两个平行板之间的强相互作用致密硬球系统，以解决三维到二维转变本质的基本问题。随着流体受到越来越强的限制，横向和侧向自由度的动力学解耦，同时伴随着将二维与三维行为分开的发散时间尺度。依靠横向动能的时间关联函数，探索了标度行为及其密度依赖性。令人惊讶的是，我们的模拟表明其时间依赖性变为纯指数形式，以至于记忆效应可以忽略不计。我们根据一种解析理论对我们的发现进行了定量合理化，该理论在强限制极限下变得精确。
