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Nearest-neighbor resonating valence bonds in YbMgGaO4

Strongly Correlated Electrons 2017-06-23 v1 Materials Science Superconductivity

Abstract

Since its proposal by Anderson, resonating valence bonds (RVB) formed by a superposition of fluctuating singlet pairs have been a paradigmatic concept in understanding quantum spin liquids (QSL). Here, we show that excitations related to singlet breaking on nearest-neighbor bonds describe the high-energy part of the excitation spectrum in YbMgGaO4, the effective spin-1/2 frustrated antiferromagnet on the triangular lattice, as originally considered by Anderson. By a thorough single-crystal inelastic neutron scattering (INS) study, we demonstrate that nearest-neighbor RVB excitations account for the bulk of the spectral weight above 0.5 meV. This renders YbMgGaO4 the first experimental system where putative RVB correlations restricted to nearest neighbors are observed, and poses a fundamental question of how complex interactions on the triangular lattice conspire to form this unique many-body state.

Keywords

Cite

@article{arxiv.1704.06468,
  title  = {Nearest-neighbor resonating valence bonds in YbMgGaO4},
  author = {Yuesheng Li and Devashibhai Adroja and David Voneshen and Robert I. Bewley and Qingming Zhang and Alexander A. Tsirlin and Philipp Gegenwart},
  journal= {arXiv preprint arXiv:1704.06468},
  year   = {2017}
}

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To be published in Nature Communications