Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolution we successfully predict a dislocation density of 1.5 × 1012 cm−2 within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.
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机译：位错是结晶固体中永久变形的主要因素。自半个多世纪以来对超音速位错的理论预测以来，缺乏支持它们存在的实验证据。在这里，我们使用受激硅的非平衡分子动力学模拟来揭示瞬态超音速部分位错运动，速度约为15 approximatelykm / s，比任何先前的硅内观测都快。均质位错形核发生在激波前沿附近，超音速位错运动仅持续几皮秒的时间，然后位错抓住激波前沿并减速回到弹性波速度。应用修正的解析方程进行位错演化，我们成功地预测了在冲击体积内的位错密度为1.5×10 12 cm −2 ，与目前的模拟结果和现实的关于先前和正在进行的硅回收实验。
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