Vison states and confinement transitions of Z2 spin liquids on the kagome lattice

TL;DR

This paper analyzes the symmetry properties and phase transitions of Z2 spin liquids on the kagome lattice, focusing on vison excitations and their role in confinement and valence bond solid order.

Contribution

It provides a detailed PSG classification of vison excitations and explores the quantum phase transition involving vison condensation on the kagome lattice.

Findings

Visons transform under specific symmetry groups (GL(2, Z3) and D3).

Quantum phase transition involves vison condensation leading to valence bond solid order.

Classified critical theories for vison-driven confinement transitions.

Abstract

We present a projective symmetry group (PSG) analysis of the spinless excitations of Z2 spin liquids on the kagome lattice. In the simplest case, vortices carrying Z2 magnetic flux ('visons') are shown to transform under the 48 element group GL(2, Z3). Alternative exchange couplings can also lead to a second case with visons transforming under 288 element group GL(2, Z3) \times D3. We study the quantum phase transition in which visons condense into confining states with valence bond solid order. The critical field theories and confining states are classified using the vison PSGs.