Abstract
We discuss the short-range resonating-valence-bond system as realized by a quantum hard-core dimer gas of arbitrary density on a two-dimensional square lattice. When the dimers completely cover the lattice, we argue that there is a first-order transition from a dimer crystal to an insulating quantum liquid state which possesses low-energy, neutral, spinless excitations which we call "resonons." For less than close-packed densities, the ground state is a superfluid. In addition to the usual Goldstone mode, there are low-energy, spinless zone-boundary excitations.
- Received 21 March 1988
DOI:https://doi.org/10.1103/PhysRevLett.61.2376
©1988 American Physical Society