Spin-1/2 Heisenberg antiferromanget on kagome: a $Z_2$ spin liquid with fermionic spinons

TL;DR

This paper develops a theoretical model for fermionic spinons in the spin-1/2 Heisenberg antiferromagnet on kagome, revealing a $Z_2$ spin liquid ground state with specific spectral properties, aligning with recent numerical and experimental findings.

Contribution

It introduces a many-body fermionic spinon model with a $Z_2$ liquid ground state, incorporating interactions with an emergent gauge field, advancing understanding of kagome antiferromagnets.

Findings

Ground state is a $Z_2$ spin liquid.

Calculated the two-spinon continuum edge.

Compared theory with slave-fermion approach.

Abstract

Motivated by recent numerical and experimental studies of the spin-1/2 Heisenberg antiferromagnet on kagome, we formulate a many-body model for fermionic spinons introduced by us earlier [Phys. Rev. Lett. 103, 187203 (2009)]. The spinons interact with an emergent U(1) gauge field and experience strong short-range attraction in the S=0 channel. The ground state of the model is generically a $Z_2$ liquid. We calculate the edge of the two-spinon continuum and compare the theory to the slave-fermion approach to the Heisenberg model.