Quantum Phase Transitions And Entanglement In J(1)-J(2) Model

We study ground state pairwise entanglement within one-dimensional spin-1/2 anti-ferromagnetic J(1)-J(2) model with competing interactions. Contrary to some claims we found that frustration does not increase entanglement. Concurrence of nearest and next nearest neighbors are found to show abrupt change at phase transition points. We also show that the concurrence can be used to classify the phase diagram of the model in anisotropy-frustration plane.