First- order versus unconventional phase transitions in three-dimensional dimer models

TL;DR

This paper investigates phase transitions in 3D classical dimer models, revealing how additional interactions influence the order and universality class of the transition, including the existence of a multicritical point and unconventional transitions.

Contribution

It demonstrates that weak symmetry-preserving interactions can change the transition from continuous to first-order and identifies a critical line of unconventional transitions.

Findings

Weak additional interactions induce first-order transitions.

The universality class remains continuous with weakly repulsive interactions.

A multicritical point and a critical line of unconventional transitions are identified.

Abstract

We study the phase transition between the Coulomb liquid and the columnar crystal in the 3D classical dimer model, which was found to be continuous in the O(3) universality class. In addition to nearest neighbor interactions which favor parallel dimers, further neighbor interactions are allowed in such a manner that the cubic symmetry of the original system remains intact. We show that the transition in the presence of weak additional, symmetry preserving interactions is first-order. However the universality class of the transition remains continuous when the additional interactions are weakly repulsive. In this way, we verify the existence of a multicritical point near the unperturbed transition and we identify a critical line of unconventional transitions between the Coulomb liquid phase and the $6-$fold columnar phase.