Lindenberg A M, Larsson J, Sokolowski-Tinten K, Gaffney K J, Blome C, Synnergren O, Sheppard J, Caleman C, Macphee A G, Weinstein D, Lowney D P, Allison T K, Matthews T, Falcone R W, Cavalieri A L, Fritz D M, Lee S H, Bucksbaum P H, Reis D A, Rudati J, Fuoss P H, Kao C C, Siddons D P, Pahl R, Als-Nielsen J, Duesterer S, Ischebeck R, Schlarb H, Schulte-Schrepping H, Tschentscher Th, Schneider J, von der Linde D, Hignette O, Sette F, Chapman H N, Lee R W, Hansen T N, Techert S, Wark J S, Bergh M, Huldt G, van der Spoel D, Timneanu N, Hajdu J, Akre R A, Bong E, Krejcik P, Arthur J, Brennan S, Luening K, Hastings J B
Stanford Synchrotron Radiation Laboratory/Stanford Linear Accelerator Center (SLAC), Menlo Park, CA 94025, USA.
Science. 2005 Apr 15;308(5720):392-5. doi: 10.1126/science.1107996.
The motion of atoms on interatomic potential energy surfaces is fundamental to the dynamics of liquids and solids. An accelerator-based source of femtosecond x-ray pulses allowed us to follow directly atomic displacements on an optically modified energy landscape, leading eventually to the transition from crystalline solid to disordered liquid. We show that, to first order in time, the dynamics are inertial, and we place constraints on the shape and curvature of the transition-state potential energy surface. Our measurements point toward analogies between this nonequilibrium phase transition and the short-time dynamics intrinsic to equilibrium liquids.
原子在原子间势能面上的运动是液体和固体动力学的基础。基于加速器的飞秒X射线脉冲源使我们能够直接追踪光学改性能量景观上的原子位移，最终导致从晶体固体向无序液体的转变。我们表明，在时间的一阶近似下，动力学是惯性的，并且我们对过渡态势能面的形状和曲率施加了限制。我们的测量结果表明，这种非平衡相变与平衡液体固有的短时间动力学之间存在相似之处。
