论文标题
在超临界状态下的动力不稳定和混乱的跨界
Crossover of dynamical instability and chaos in the supercritical state
论文作者
论文摘要
我们计算恒定能量分子动力学中的256个Lennard-Jones颗粒的散装系统的最大Lyapunov指数，深入到了超临界状态。我们发现，最大的Lyapunov指数经历了交叉，并且这种交叉与液体物理学的Frenkel系列的动力跨界相吻合。我们用两种对动态不稳定性的贡献来解释这一交叉：在弗伦克尔线以下的液体状状态中的扩散以及上面类似气体状态的碰撞。这些结果提供了远离熔融线和稀有气体近似不可能的密度远处的相空间动力学的见解。
We calculate the maximal Lyapunov exponent for a bulk system of 256 Lennard-Jones particles in constant energy molecular dynamics simulations deep into the supercritical state. We find that the maximal Lyapunov exponent undergoes a crossover, and that this crossover coincides with the dynamical crossover at the Frenkel line from liquid physics. We explain this crossover in terms of two different contributions to dynamical instability: diffusion in the liquid-like state below the Frenkel line, and collisions in the gas-like state above. These results provide insight into the phase space dynamics far from the melting line and densities where rare-gas approximation are inapplicable.
