Ground-state properties and quantum entanglement in rung-dimerized spin-1/2 antiferromagnetic ladder

The ground-state properties and quantum entanglement of the two-leg rung-dimerized spin-1/2 Heisenberg antiferromagnetic ladders are investigated based on the Greenʼ function combined with the Bond mean-field theory. Numerical results show that the ground-state energies do not change with the rung dimerization, and the ground-state gaps are almost proportionate to the rung dimerization coefficient δ and coupling strength α. Magnetization curves and entanglement measurements demonstrate that there are five magnetic phases, which are identified in the h-δ phase diagram. Entanglement measurements in different phases exhibit distinct behaviors, implying the fundamental differences of the five magnetic phases.