Pruneda J M, Sánchez-Portal D, Arnau A, Juaristi J I, Artacho Emilio
Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC) Campus de Bellaterra, 08193 Barcelona, Spain.
Phys Rev Lett. 2007 Dec 7;99(23):235501. doi: 10.1103/PhysRevLett.99.235501. Epub 2007 Dec 3.
Using time-dependent density-functional theory we calculate from first principles the rate of energy transfer from a moving proton or antiproton to the electrons of an insulating material, LiF. The behavior of the electronic stopping power versus projectile velocity displays an effective threshold velocity of approximately 0.2 a.u. for the proton, consistent with recent experimental observations, and also for the antiproton. The calculated proton/antiproton stopping-power ratio is approximately 2.4 at velocities slightly above the threshold (v approximately 0.4 a.u.), as compared to the experimental value of 2.1. The projectile energy loss mechanism is observed to be extremely local.
我们使用含时密度泛函理论，从第一性原理出发计算了移动的质子或反质子向绝缘材料LiF的电子传递能量的速率。电子阻止本领与入射粒子速度的关系表明，质子存在一个约为0.2 a.u.的有效阈速度，这与最近的实验观测结果一致，反质子的情况也是如此。在略高于阈速度（v约为0.4 a.u.）时，计算得到的质子/反质子阻止本领比约为2.4，而实验值为2.1。我们观察到入射粒子的能量损失机制具有极强的局域性。
