The quantum $J_1$-$J_1'$-$J_2$ spin-1/2 Heisenberg model: Influence of the interchain coupling on the ground-state magnetic ordering in 2D

TL;DR

This study explores how interchain coupling influences magnetic orderings in a 2D quantum spin model, revealing shifts in quantum critical points and the emergence of an intermediate phase using the coupled cluster method.

Contribution

It provides new insights into the phase diagram of the 2D $J_1$-$J_1'$-$J_2$ Heisenberg model, identifying a quantum triple point and the effects of interchain coupling.

Findings

Quantum critical points increase with $J_1'$

Emergence of an intermediate phase at $J_1' \, \approx \, 0.6$

Identification of a quantum triple point near specific coupling values

Abstract

We study the phase diagram of the 2D $J_1$-$J_1'$-$J_2$ spin-1/2 Heisenberg model by means of the coupled cluster method. The effect of the coupling $J_1'$ on the Neel and stripe states is investigated. We find that the quantum critical points for the Neel and stripe phases increase as the coupling strength $J_1'$ is increased, and an intermediate phase emerges above the region at $J_1' \approx 0.6$ when $J_1=1$. We find indications for a quantum triple point at $J_1' \approx 0.60 \pm 0.03$, $J_2 \approx 0.33 \pm 0.02$ for $J_1=1$.