1. The random force in molecular dynamics with electronic friction
- Author
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Hertl, Nils, Martin-Barrios, Raidel, Galparsoro, Oihana, Larregaray, Pascal, Auerbach, Daniel J., Schwarzer, Dirk, Wodtke, Alec M., and Kandratsenka, Alexander
- Subjects
Statistical Mechanics (cond-mat.stat-mech) ,FOS: Physical sciences ,Condensed Matter - Statistical Mechanics - Abstract
The Langevin equation includes a random force to maintain equilibrium and prevent friction from bringing motion to a standstill; but for ballistic motion, the random force is often neglected. Here, we use the Langevin equation for molecular dynamics simulations of 2.76 eV H-atoms experiencing electronic friction in collisions with 300 K metals, where a random force arises from thermal electron-hole pairs. Simulations without the random force fail dramatically to reproduce experiment, although the incidence energy is much larger than $k_\text{B}T$. We analyze the Ornstein-Uhlenbeck process to show that this is a general property of ballistic particles experiencing friction under the influence of thermal fluctuations., Comment: submitted to PRL
- Published
- 2021
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