Figure 2.

Membrane structure in the disordered fluid phase, i.e., regions f₁ and f₂ of the phase diagram (data for J = 0.4, L = 200, with the lattice constant a as the unit of length). (a) Static structure factor, S(q), for curvature-composition coupling, γ = 0, 1, 2, 3, 4, 5 (from top to bottom). When γ = 0, S(q) assumes its maximum at q = 0, characteristic of region f₁. When γ > γ_Lif, the maximum occurs at a finite value, q^∗ > 0 (region f₂), and shifts to larger q as γ increases. In region f₂, the membrane resembles a raft phase, with composition fluctuations of typical size l^∗. (b) Comparison between the simulated S(q) (data) and the mean-field form Eq. 6 for γ = 3 (fit). (c) l^∗, as computed via Eq. 20, as a function of γ, for several values of J. As γ increases, the curves approach the theoretical estimate ∼(κ/σ)^1/2 (18) (indicated by the horizontal line). To see this figure in color, go online.