Algebraic spin liquid in an exactly solvable spin model

TL;DR

This paper introduces an exactly solvable spin-3/2 model on a square lattice that exhibits an algebraic spin liquid ground state with stable gapless Dirac fermions and gapped vison excitations.

Contribution

It presents the first exactly solvable model of a half-integer spin system with an algebraic spin liquid ground state.

Findings

Ground state is a quantum spin liquid with half-integer spins.

Fermionic excitations are gapless with linear dispersion.

Topological vison excitations are gapped.

Abstract

We have proposed an exactly solvable quantum spin-3/2 model on a square lattice. Its ground state is a quantum spin liquid with a half integer spin per unit cell. The fermionic excitations are gapless with a linear dispersion, while the topological "vison" excitations are gapped. Moreover, the massless Dirac fermions are stable. Thus, this model is, to the best of our knowledge, the first exactly solvable model of half-integer spins whose ground state is an "algebraic spin liquid."