Simulation of a liquid-vapor interface in an external field

The influence of gravity on the suppression of the capillary fluctuations of a liquid-vapour interface is studied by simulating a Lennard-Jones system in two dimensions in a gravity like field. The results are compared to the capillary wave theory. A lower length cut-off is found for the capillary wavelengths which is an order of magnitude larger than the estimated width of the intrinsic interface.