Inelastic Neutron Scattering from the Spin Ladder Compound (VO)2P2O7

TL;DR

This study uses inelastic neutron scattering to confirm the existence of a spin-wave excitation gap in (VO)2P2O7, providing the first natural evidence of a Heisenberg antiferromagnetic spin ladder.

Contribution

It presents the first experimental confirmation of a Heisenberg antiferromagnetic spin ladder in (VO)2P2O7 through neutron scattering measurements.

Findings

Detected a spin-wave gap of 3.7 meV near Q=0.8 A^{-1}

Confirmed the spin-ladder model for (VO)2P2O7

First natural evidence of a Heisenberg antiferromagnetic spin ladder

Abstract

We present results from an inelastic neutron scattering experiment on the candidate Heisenberg spin ladder vanadyl pyrophosphate, (VO)2P2O7. We find evidence for a spin-wave excitation gap of $E_{gap} = 3.7\pm 0.2$ meV, at a band minimum near $Q=0.8 A^{-1}$. This is consistent with expectations for triplet spin waves in (VO)2P2O7 in the spin-ladder model, and is to our knowledge the first confirmation in nature of a Heisenberg antiferromagnetic spin ladder.