Tricritical wedge filling transitions with short-ranged forces

TL;DR

This paper investigates how short-ranged forces influence the order of 3D wedge filling transitions, revealing the existence of a tricritical point and connecting it to 2D wetting with disorder.

Contribution

It introduces a one-dimensional model for 3D wedge filling that captures the transition's nature and identifies conditions for tricritical behavior.

Findings

Transition order depends on line tension strength.

Existence of a tricritical point with unique short-distance behavior.

Connection between 3D filling and 2D wetting with disorder.

Abstract

We show that the 3D wedge filling transition in the presence of short-ranged interactions can be first-order or second order depending on the strength of the line tension associated with to the wedge bottom. This fact implies the existence of a tricritical point characterized by a short-distance expansion which differs from the usual continuous filling transition. Our analysis is based on an effective one-dimensional model for the 3D wedge filling which arises from the identification of the breather modes as the only relevant interfacial fluctuations. From such analysis we find a correspondence between continuous 3D filling at bulk coexistence and 2D wetting transitions with random-bond disorder.