Spin-Peierls states of quantum antiferromagnets on the $Ca V_4 O_9$ lattice

TL;DR

This paper investigates quantum paramagnetic phases in Heisenberg antiferromagnets on the $Ca V_4 O_9$ lattice, revealing a new spin-Peierls phase with broken lattice symmetry through a quantum dimer model mapping.

Contribution

It introduces a novel intermediate spin-Peierls phase in the quantum dimer model on the $Ca V_4 O_9$ lattice, expanding understanding of quantum paramagnetic states.

Findings

Identification of a possible spin-Peierls phase with broken lattice symmetry.

Mapping of the quantum dimer model to a height model for phase analysis.

Discussion of experimental signatures for different phases.

Abstract

We discuss the quantum paramagnetic phases of Heisenberg antiferromagnets on the 1/5-depleted square lattice found in $Ca V_4 O_9$. The possible phases of the quantum dimer model on this lattice are obtained by a mapping to a quantum-mechanical height model. In addition to the ``decoupled'' phases found earlier, we find a possible intermediate spin-Peierls phase with spontaneously-broken lattice symmetry. Experimental signatures of the different quantum paramagnetic phases are discussed.