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

A spin-1/2 Heisenberg model on a honeycomb lattice is investigated by doing triplon analysis and quantum Monte Carlo calculations. This model, inspired ${\mathrm{Cu}}_{2}{(\mathrm{pymca})}_{3}({\mathrm{ClO}}_{4}$), has three different antiferromagnetic exchange interactions (${J}_{A}, {J}_{B}, {J}_{C}$) sets of nearest-neighbor bonds which form kagome superlattice. While the bipartite unfrustrated, its phase diagram found to be dominated paramagnetic that best described as spin-gapped hexagonal-singlet state. The N\'eel order survives only in small region around ${J}_{A}={J}_{B}={J}_{C}$. magnetization produced external magnetic field exhibit plateaus at 1/3 2/3 saturation value, or alone, no plateaus. Notably, exist inside bounded within phase. study provides clear understanding behavior observed also predicts possible disappearance plateau under pressure.