Phase Diagram of the Spin-1/2 Heisenberg Alternating Chain in a Magnetic Field *

Wei-Xia Chen,Jie Ren,Wen-Long You,Xiang Hao,Yin-Zhong Wu

Fig. 5 (Color online) Entanglement entropy $S_L$ between contiguous $L$ qubits and theremaining $N-L$ qubits is plotted as a function of $L$ and $\log_2[({N}/{\pi}) \sin({\pi L}/{N})]$ (inset) for $N=400$. The lines are the numerical fittings.