Plaquette valence bond solid in the frustrated Heisenberg quantum antiferromagnet on the square lattice

M. Mambrini, A. Laeuchli, D. Poilblanc +1

Using both exact diagonalizations and diagonalizations in a subset of short-range valence bond singlets, we address the nature of the groundstate of the Heisenberg spin-1/2 antifer…