Unbinding of symmetric and asymmetric stacks of membranes

The unbinding of N membranes interacting with attractive potentials is considered theoretically for zero pressure. In the symmetric case, for which the membranes have the same bending rigidity, all N membranes unbind simultaneously at the N-independent temperature ${\mathit{T}}_{\mathit{c}}^{\mathit{s}}$ but with N-dependent effective critial exponents. In the asymmetric case, for which the lowest membrane acts as a rigid wall, they exhibit a sequence of unbinding transitions with universal exponents; the transition temperature of the uppermost membrane for a semi-infinite stack (N=∞) is again given by ${\mathit{T}}_{\mathit{c}}^{\mathit{s}}$.