The transition from an ordered antiferromagnet to a quantum disordered spin liquid in a solvable bilayer model

TL;DR

This paper introduces a solvable bilayer spin-1/2 model that captures the quantum transition from an ordered antiferromagnet to a disordered spin liquid, incorporating frustration effects and providing analytical and numerical insights.

Contribution

It presents a new solvable bilayer model for quantum phase transition analysis, including frustration, with analytical and numerical results for critical properties.

Findings

Critical coupling decreases linearly with frustration.

Mean-field theory accurately describes bulk quantities.

Analytical and numerical results agree on transition parameters.

Abstract

We present a spin-1/2 bilayer model for the quantum order-disorder transition which (i) can be solved by mean-field theory for bulk quantities, (ii) becomes critical at the transition, and (iii) allows to include intralayer frustration. We present numerical data (for systems with up to 240 sites) and analytical results for the critical coupling strength, ground-state energy, order parameter and for the gap. We show that the critical coupling decreases linearly with frustration.