Quantum paramagnetism and magnetization plateaus in a kagome-honeycomb Heisenberg antiferromagnet

Abstract

A spin-1/2 Heisenberg model on honeycomb lattice is investigated by doing triplon analysis and quantum Monte Carlo calculations. This model, inspired by Cu${}_2$(pymca)${}_3$(ClO${}_4$), has three different antiferromagnetic exchange interactions ($J_A$, $J_B$, $J_C$) on three different sets of nearest-neighbour bonds which form a kagome superlattice. While the model is bipartite and unfrustrated, its quantum phase diagram is found to be dominated by a quantum paramagnetic phase that is best described as a spin-gapped hexagonal-singlet state. The Néel antiferromagnetic order survives only in a small region around $J_A=J_B=J_C$. The magnetization produced by external magnetic field is found to exhibit plateaus at 1/3 and 2/3 of the saturation value, or at 1/3 alone, or no plateaus. Notably, the plateaus exist only inside a bounded region within the hexagonal-singlet phase. This study provides a clear understanding of the spin-gapped behaviour and magnetization plateaus observed in Cu${}_2$(pymca)${}_3$(ClO${}_4$), and also predicts the possible disappearance of 2/3 plateau under pressure.

16 pages, 14 figures

References in corpus (6)

• Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2
• Vesignieite BaCu3V2O8(OH)2 as a Candidate Spin-1/2 Kagome Antiferromagnet
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Cited by in corpus (6)

• Effective spin-1 breathing kagome Hamiltonian induced by the exchange hierarchy in the maple leaf mineral bluebellite
• Temperature flow in pseudo-Majorana functional renormalization for quantum spins
• Entanglement and quantum correlations in the XX spin-$1/2$ honeycomb lattice
• Low-energy spin dynamics in a Kitaev material Na3Ni2BiO6 investigated by NMR
• Magnetic structure, excitations and field induced transitions in the honeycomb lattice $\mathrm{E}{\mathrm{r}}_2\mathrm{S}{\mathrm{i}}_2{\mathrm{O}}_7$
• Magnetic excitations from the hexagonal spin clusters in the S = 1/2 distorted honeycomb lattice antiferromagnet Cu2(pymca)3(ClO4)