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A renormalised hamiltonian approach for a resonant valence bond wavefunction

F. C. Zhang·C. Gros·T. M. Rice·H. Shiba
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Abstract

The effective Hamiltonian of strongly correlated electrons on a square lattice is replaced by a renormalised Hamiltonian and the factors that renormalise the kinetic energy of holes and the Heisenberg spin-spin coupling are calculated using a Gutzwiller approximation scheme. The accuracy of this renormalisation procedure is tested numerically and found to be qualitatively excellent. Within the scheme a resonant valence bond (RVB) wavefunction is found at half-filling to be lower in energy than the antiferromagnetic state. If the wavefunction is expressed in fermion operators, local SU(2) and U(l) invariance leads to a redundancy in the representation. The introduction of holes removes these local invariances and we find that a d-wave RVB state is lowest in energy. This state has a superconducting order parameter whose amplitude is linear in the density of holes.

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F. C. Zhang, C. Gros, T. M. Rice, H. Shiba. 2003-11-26. A renormalised hamiltonian approach for a resonant valence bond wavefunction. https://arxiv.org/abs/cond-mat/0311604

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