Ground State and Intrinsic Susceptibility of the Kagome Antiferromagnet Vesignieite as seen by 51V NMR

TL;DR

This study uses 51V NMR to investigate the magnetic properties of vesignieite, revealing a transition to a heterogeneous ground state at 9 K likely driven by quantum criticality and Dzyaloshinskii-Moriya interactions.

Contribution

First detailed NMR analysis of vesignieite's intrinsic susceptibility and ground state, linking observed phenomena to quantum criticality and magnetic interactions.

Findings

Intrinsic susceptibility resembles that of quantum spin liquids

Transition to a heterogeneous ground state at ~9 K

Evidence of static magnetism onset at certain sites

Abstract

The intrinsic magnetic susceptibility and local magnetization of the near-kagome quantum magnet vesignieite, Cu3BaV2O8(OH)2, are presented as measured using 51V NMR. The NMR line shift gives an accurate measurement of the intrinsic susceptibility of the kagome sites which closely resembles that of the quantum spin liquid herbertsmithite [A. Olariu et al. Phys. Rev. Lett. 100, 087202 (2008)]. It is therefore surprising that, at Tc ~ 9 K, a transition to a heterogeneous ground state is observed. A gradual wipeout of half the NMR intensity indicates a slowly fluctuating spin liquid component and a detailed analysis of the linewidth reveals the onset of static magnetism at the remaining half of the sites. It is proposed that this transition and unusual ground state originate from a nearby quantum critical point induced by the Dzyaloshinskii-Moriya interaction.