Revealing quantum spin liquid in the herbertsmithite $\rm ZnCu_{3}(OH)_6Cl_{2}$

TL;DR

This paper proposes experimental strategies to definitively identify gapless quantum spin liquid states in herbertsmithite and similar materials, emphasizing measurements under magnetic fields and impurity effects.

Contribution

It offers a comprehensive approach combining experimental measurements and theoretical analysis to unambiguously establish the presence of gapless QSL in herbertsmithite.

Findings

Predicted heat transport and neutron scattering signatures of gapless QSL.

Suggested impurity inhomogeneity stabilizes QSL and helps distinguish impurity effects.

Provided a strategy for experimental verification of QSL in herbertsmithite.

Abstract

Based on experimental data and our theoretical analysis, we provide a strategy for unambiguous establishing of gapless quantum spin liquid state (QSL) in herbertsmithite and other materials. To clarify the nature of QSL, we recommend measurements of heat transport, low-energy inelastic neutron scattering and optical conductivity under the application of external magnetic field at low temperatures. We also suggest that artificially introduced inhomogeneity into $\rm ZnCu_{3}(OH)_6Cl_2$ can stabilize QSL, and serves as a test elucidating the contribution coming from impurities. We predict the results of these measurements in the case of gapless QSL.