arXiv:cond-mat/9904286 · Physical review. B, Condensed matter
Dimer–resonating valence bond state of the four-leg Heisenberg ladder: Interference among resonances
M. Roncaglia, Germán Sierra, Miguel Angel Martin-Delgado
Abstract
We study the ground state of the four-leg spin ladder using a dimer--resonating valence bond (RVB) ansatz and the Lanczos method. Besides the well-known resonance mechanism between valence bond configurations we find interference effects among nearby resonances. These effects were missed by standard factorizing approaches to the RVB states.