A renormalised hamiltonian approach for a resonant valence bond wavefunction
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.
Cite
@article{arxiv.cond-mat/0311604,
title = {A renormalised hamiltonian approach for a resonant valence bond wavefunction},
author = {F. C. Zhang and C. Gros and T. M. Rice and H. Shiba},
journal= {arXiv preprint arXiv:cond-mat/0311604},
year = {2007}
}
Comments
reproduced for reader's convenience. one of key references in cond-mat/0311467. Reprint at http://www.physics.hku.hk/~fczhang