The quantum J1-J1'-J2 spin-1/2 Heisenberg model:: influence of the interchain coupling on the ground-state magnetic ordering in two dimensions

We study the phase diagram of the two-dimensional (2D) J(1)-J(1)(')-J(2) spin-1/2 Heisenberg model by means of the coupled cluster method. The effect of the coupling J(1)(') on the Neel and stripe states is investigated. We find that the quantum critical points for the Neel and stripe phases increase as the coupling strength J(1)(') is increased, and an intermediate phase emerges above the region at J(1)(') approximate to 0.6 when J(1) = 1. We find indications for a quantum triple point at J(1)(') approximate to 0.60 +/- 0.03, J(2) approximate to 0.33 +/- 0.02 for J(1) = 1.