Evidence for a Gapped Spin-Liquid Ground State in a Kagome Heisenberg Antiferromagnet

2015/11/06 by M. Fu, T. Imai, T. -H. Han +1 · 3 citations
Physics and Astronomy · #cond-mat.str-el #cond-mat.stat-mech #cond-mat.supr-con

paper · pdf · doi:10.1126/science.aab2120

published as Science 350 (2015) 655 · Version accepted for publication in Science

arxiv created 2015/11/06 · arxiv updated 2015/11/09

Abstract

The kagome Heisenberg antiferromagnet is a leading candidate in the search for a spin system with a quantum spin-liquid ground state. The nature of its ground state remains a matter of great debate. We conducted 17-O single crystal NMR measurements of the S=1/2 kagome lattice in herbertsmithite ZnCu₃(OH)₆Cl₂, which is known to exhibit a spinon continuum in the spin excitation spectrum. We demonstrate that the intrinsic local spin susceptibility χ_kagome deduced from the 17-O NMR frequency shift asymptotes to zero below temperature T ~ 0.03 J, where J ~ 200 K is the Cu-Cu super-exchange interaction. Combined with the magnetic field dependence of χ_kagome we observed at low temperatures, these results imply that the kagome Heisenberg antiferromagnet has a spin-liquid ground state with a finite gap.

Cited by

• Nature of the 1/3 Magnetization Plateau in Spin-1/2 Kagome Antiferromagnets
• Dynamical spin correlations in kagome antiferromagnets: comparison of Abrikosov fermion and Schwinger boson approaches beyond mean field
• Quantifying the Phase Diagram and Hamiltonian of S=1/2 Kagome Antiferromagnets: Bridging Theory and Experiment

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