Valence bond order in a honeycomb antiferromagnet coupled to quantum phonons

Transitions to Valence-Bond Solid Order in a Honeycomb Lattice Antiferromagnet

Supersolid phases of a doped valence-bond quantum antiferromagnet: evidence for a coexisting superconducting order parameter.

Motivated by numerical evidence of the valence-bond ground state of the two-dimensional Heisenberg pyrochlore lattice, we argue using a t-J model that it evolves under doping into novel phases characterized by superconductivity coexisting with the underlying valence-bond solid order. A fermionic mean-field theory supplemented by exact diagonalization results provide strong arguments in favor of...

Valence bond solid phases in a cubic antiferromagnet.

We report on a valence bond projector Monte Carlo simulation of the cubic lattice quantum Heisenberg model with additional higher-order exchange interactions in each unit cell. The model supports two different valence bond solid (VBS) ground states. In one of these states, the dimer pattern is a three-dimensional analogue of the columnar pattern familiar from two dimensions. In the other, the d...

Bosonic Resonating-Valence-Bond Description of a Doped Antiferromagnet

We propose a theory for a doped antiferromagnet based on the bosonic resonating-valence-bond (RVB) description incorporating the phase string effect. Both antiferromagnetic and superconducting phase transitions occur naturally inside such a bosonic RVB phase. Two distinct metallic regions— underdoping and optimum doping—are also found to be a logical consequence; their unique features explain t...

Heisenberg Antiferromagnet on Square-Kagomé Lattice: Resonating Valence Bond Description