Quantum disordered phase on the frustrated honeycomb lattice

TL;DR

This paper investigates the phase diagram of the frustrated Heisenberg model on the honeycomb lattice, revealing a quantum disordered phase with a spin gap and short-range correlations, supported by multiple computational techniques.

Contribution

It introduces evidence for a quantum disordered phase in the frustrated honeycomb lattice Heisenberg model using combined analytical and numerical methods.

Findings

Existence of a quantum disordered phase with a spin gap

Short-range Néel correlations in the disordered phase

Consistent results across multiple computational techniques

Abstract

In the present paper we study the phase diagram of the Heisenberg model on the honeycomb lattice with antiferromagnetic interactions up to third neighbors along the line $J_2=J_3$ that include the point $J_2=J_3=J_1/2$, corresponding to the highly frustrated point where the classical ground state has macroscopic degeneracy. Using the Linear Spin-Wave, Schwinger boson technique followed by a mean field decoupling and exact diagonalization for small systems we find an intermediate phase with a spin gap and short range N\'eel correlations in the strong quantum limit (S=1/2). All techniques provide consistent results which allow us to predict the existence of a quantum disordered phase, which may have been observed in recent high-field ESR measurements in manganites.