Langevin dynamics of a surface crystal atom subject to a time-dependent external force
Abstract
The paper considers the 001-plane surface of a semiinfinite Rosenstock Newell crystal, one of whose atoms is subject to an arbitrary time-dependent external force. The dynamics of the crystal is investigated by dividing the displacement vector of the general atom into a contribution due to the external force and a fluctuating part associated with thermal motions. Thermalization of the system is obtained by embedding the crystal into a virtual viscous fluid and writing the corresponding many-body Langevin equation. Dynamic quantities of the real crystal, such as average displacements and autocorrelation functions, are calculated by letting the friction coefficient of the fluid go to zero. Image reflection techniques are introduced both for the time-dependent external force and for the Langevin random forces, in order to account for the existence of the free crystal surface.
- Publication:
-
Rarefied Gas Dynamics
- Pub Date:
- 1979
- Bibcode:
- 1979rgd..conf.1381L
- Keywords:
-
- Atomic Physics;
- Crystal Surfaces;
- Cubic Lattices;
- Autocorrelation;
- Displacement;
- Time Dependence;
- Atomic and Molecular Physics