Spin-1/2 J1-J2 Heisenberg antiferromagnet on a square lattice: A plaquette renormalized tensor network study

We apply the plaquette renormalization scheme of tensor network states [Phys. Rev. E 83, 056703 (2011)] to study the spin-1/2 frustrated Heisenberg J(1)-J(2) model on an L x L square lattice with L = 8, 16, and 32. By treating tensor elements as variational parameters, we obtain the ground states for different J(2)/J(1) values, and investigate staggered magnetizations, nearest-neighbor spin-spin correlations, and plaquette order parameters. In addition to the well-known Neel order and collinear order at low and high J(2)/J(1), we observe a plaquettelike order at J(2)/J(1) approximate to 0.5. A continuous transition between the Neel order and the plaquettelike order near J(2)(c1) approximate to 0.40J(1) is observed. The collinear order emerges at J(2)(c2) approximate to 0.62J(1) through a first-order phase transition.