Study of the dynamic growth of wetting layers in the confined Ising model with competing surface fields

EZEQUIEL V ALBANO; A DE VIRGILIS,; M MÜLLER,; BINDER, K

JOURNAL OF PHYSICS CONDENSED MATTER

IOP

Año: 2006 vol. 18 p. 2761 - 2775

0953-8984

A two-dimensional magnetic Ising system confined in an L × D geometry (L << D) in the presence of competing magnetic fields (h) acting at opposite walls along the D-direction exhibits an interface between domains of different orientation that runs parallel to the walls. In the limit of infinite film thickness (L → ∞) this interface undergoes a wetting transition that occurs at the critical curve Tw(h), so that for T<Tw(h) such an interface is bound to the walls, while for Tw(h)≤T≤Tcb the interface is freely fluctuating around the centre of the film, where Tcb is the bulk critical temperature. Starting from a monodomain structure with the interface bound to one wall, we study the onset of the interface unbinding by considering both short- and long-range magnetic fields acting at the walls. It is shown that, within the critical wetting regime, in both cases the correlation length of interfacial fluctuations ξ  grows with time t as  ξ  α t1/z with z = 2, while the interfacial position follows Z(t) α t1/2z both in the case of short-range and long-range surface fields, respectively, consistent with dynamic scaling predictions. Furthermore, considering the complete wetting regime and in the presence of a bulk magnetic field, we find that the interface location also obeys standard dynamic scaling behaviour for both short-range and long-range fields.