Capillary Waves at the Liquid-Vapor Interface. Widom-Rowlinson Model at Low Temperature
Frank H. Stillinger
AT&T Bell Laboratories, Murray Hill, New Jersey 07974
John D. Weeks
J. Phys. Chem. 99, 2807-2816 (1995).
We have examined in detail the structure and properties of the liquid-vapor interface for the two-dimensional Widom-Rowlinson model in its low-temperature regime. Various simplifying features permit the deduction of several basic results. Included among these are (1) unambiguous definition of capillary wave modes with upper wavelength cutoff proportional to r1-1/3 (r1 = liquid density); (2) wavelength dispersion of bare surface tension; and (3) nonmonotonic intrinsic density profile (i.e., that with vanishing capillary wave amplitudes). In an Appendix we show how many of these results can be extended to the three and higher dimensional cases.