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arXiv · 2201.13369

Evidence of Two-Spinon Bound States in the Magnetic Spectrum of Ba$_3$CoSb$_2$O$_9$

E. A. Ghioldi·Shang-Shun Zhang·Yoshitomo Kamiya·L. O. Manuel·A. E. Trumper·C. D. Batista
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Abstract

Recent inelastic neutron scattering (INS) experiments of the triangular antiferromagnet Ba$_3$CoSb$_2$O$_9$ revealed strong deviations from semiclassical theories. We demonstrate that key features of the INS data are well reproduced by a parton Schwinger boson theory beyond the saddle-point approximation. The measured magnon dispersion is well reproduced by the dispersion of two-spinon bound states (poles of the emergent gauge fields propagator), while the low-energy continuum scattering is reproduced by a quasifree two-spinon continuum, suggesting that a free-spinon gas is a good initial framework to study magnetically ordered states near a quantum melting point.

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E. A. Ghioldi, Shang-Shun Zhang, Yoshitomo Kamiya, L. O. Manuel, A. E. Trumper, C. D. Batista. 2022-01-31. Evidence of Two-Spinon Bound States in the Magnetic Spectrum of Ba$_3$CoSb$_2$O$_9$. https://doi.org/10.1103/physrevb.106.064418

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