Valence Bond States: Link models

Author(s): E. Rico, R. Huebner, S. Montangero, N. Moran, B. Pirvu, J. Vala, H. J. Briegel

Journal: Annals of Physics

Volume: 324

Page(s): 1875-1896

Year: 2008

DOI Number: 10.1016/j.aop.2009.06.001

Link: Link to publication


An isotropic anti-ferromagnetic quantum state on a square lattice is characterized by symmetry arguments only. By construction, this quantum state is the result of an underlying valence bond structure without breaking

any symmetry in the lattice or spin spaces. A detailed analysis of the correlations of the quantum state is given (using a mapping to a 2D classical statistical model and to the non-linear sigma model) as well as the results of

numerical treatments (regarding exact diagonalization and variational methods). Finally, the physical relevance of the model is motivated. A comparison of the model to known anti-ferromagnetic Mott-Hubbard insulators is given by means of the two-point equal-time correlation function obtained i) numerically from the suggested state and ii) experimentally from neutron scattering on cuprates in the anti-ferromagnetic insulator phase.


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