Multicritical point of the three-dimensional Z_2 gauge Higgs model

TL;DR

This paper studies the complex multicritical behavior of the 3D Z_2 gauge Higgs model at a point where different phase transition lines meet, revealing an emergent XY symmetry and supporting this with numerical evidence.

Contribution

It identifies a multicritical XY universality class at the MCP of the 3D Z_2 gauge Higgs model, highlighting an emergent O(2) symmetry at the multicritical point.

Findings

Multicritical behavior exhibits XY universality class.

Emergent O(2) symmetry at the MCP.

Numerical results support the multicritical XY scenario.

Abstract

We investigate the multicritical behavior of the three-dimensional Z_2 gauge Higgs model, at the multicritical point (MCP) of its phase diagram, where one first-order transition line and two continuous Ising-like transition lines meet. The duality properties of the model determine some features of the multicritical behavior at the MCP located along the self-dual line. Moreover, we argue that the system develops a multicritical XY behavior at the MCP, which is controlled by the stable XY fixed point of the three-dimensional multicritical Landau-Ginzburg-Wilson field theory with two competing scalar fields associated with the continuous Z_2 transition lines meeting at the MCP. This implies an effective enlargement of the symmetry of the multicritical modes at the MCP, to the continuous group O(2). We also provide some numerical results to support the multicritical XY scenario.