 
Summary: Surface states in nearly modulated systems
A. E. Jacobs,1,2
D. Mukamel,2
and D. W. Allender3
1
Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7
2
Department of Physics of Complex Systems, The Weizmann Institute of Science, Rehovot 76100, Israel
3
Department of Physics and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242
Received 3 July 2000; published 23 January 2001
A Landau model is used to study the phase behavior of the surface layer for magnetic and cholesteric
liquidcrystal systems that are at or near a Lifshitz point marking the boundary between modulated and
homogeneous bulk phases. The model incorporates surface and bulk fields and includes a term in the free
energy proportional to the square of the second derivative of the order parameter in addition to the usual term
involving the square of the first derivative. In the limit of vanishing bulk field, three distinct types of surface
ordering are possible: a wetting layer, a nonwet layer having a small deviation from bulk order, and a different
nonwet layer with a large deviation from bulk order that decays nonmonotonically as the distance from the wall
increases. In particular, the large deviation nonwet layer is a feature of systems at the Lifshitz point and also
those systems having only homogeneous bulk phases.
