The Heisenberg model on the 1/5-depleted square lattice and the CaV4O9 compound

TL;DR

This paper explores the complex ground states of the Heisenberg model on a 1/5-depleted square lattice, revealing various magnetic phases and their relevance to the CaV4O9 compound using a mean-field Schwinger-boson approach.

Contribution

It provides a unified theoretical framework describing multiple magnetic phases of the Heisenberg model on this lattice, including implications for experimental materials.

Findings

Identification of plaquette and dimer RVB phases

Discovery of incommensurate and complex magnetic orders

Relevance to experimental CaV4O9 compound

Abstract

We investigate the ground state structure of the Heisenberg model on the 1/5-depleted square lattice for arbitrary values of the first- and second-neighbor exchange couplings. By using a mean-field Schwinger-boson approach we present a unified description of the rich ground-state diagram, which include the plaquette and dimer resonant-valence-bond phases, an incommensurate phase and other magnetic orders with complex magnetic unit cells. We also discuss some implications of ours results for the experimental realization of this model in the CaV4O9 compound.