Tensor network simulation of phase diagram of frustrated J1-J2   Heisenberg model on a checkerboard lattice
  We use the recently developed tensor network algorithm based on infinite projected entangled pair states (iPEPS) to study the phase diagram of frustrated antiferromagnetic J1-J2 Heisenberg model on a checkerboard lattice. The simulation indicates a Neel ordered phase when J2 < 0.88J1, a plaquette valence bond solid state when 0.88 < J2/J1 < 1.11, and a stripe phase when J2 > 1.11J1, with two first-order transitions across the phase boundaries. The calculation shows the cross-dimer state proposed before is unlikely to be the ground state of the model, although such a state indeed arises as a metastable state in some parameter region. 
Yang-hao Chan, Yong-jian Han and Luming Duan
cond-mat.str-el quant-ph