The Nature of Spin Excitations in the One-Third Magnetization Plateau Phase of Ba3CoSb2O9

Published

July 10, 2018

Author(s)

Y. Kamiya, L. Ge, Tao Hong, Yiming Qiu, D. L. Quintero-Castro, Z. Lu, H. B. Cao, M. Matsuda, E. S. Choi, C. D. Batista, M. Mourigal, H. D. Zhou, J. Ma

Abstract

A recent experiment revealed that the spin-1/2 triangular-lattice Heisenberg antiferromagnet Ba₃CoSb₂O₉ is a magnetically ordered material with an anomalous excitation spectrum, comprising a high-intensity excitation continuum and short-lived magnons, which cannot be explained with spin wave theory [Ma et al., Phys. Rev. Lett. 116, 087201 (2016)]. We use neutron scattering measurements in high magnetic field to map the magnetic excitations of Ba₃CoSb₂O₉ in its 1/3-magnetization plateau. This enables an investigation on the role of quantum fluctuations and the validity of a previously obtained effective spin Hamiltonian for this material. The measured excitation spectrum of the up-up-down phase induced by a magnetic field of ≥ 9.8 T is quantitatively explained by nonlinear spin wave theory. This agreement confirms the validity of the spin Hamiltonian, indicating that the anomalous zero-field spin dynamics has an intrinsic quantum mechanical origin.

Citation

Nature Communications

Volume

9

Issue

1

Pub Type

Journals

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Keywords

quantum spin liquid, neutron scattering

Citation

Kamiya, Y. , Ge, L. , Hong, T. , Qiu, Y. , Quintero-Castro, D. , Lu, Z. , Cao, H. , Matsuda, M. , Choi, E. , Batista, C. , Mourigal, M. , Zhou, H. and Ma, J. (2018), The Nature of Spin Excitations in the One-Third Magnetization Plateau Phase of Ba₃CoSb₂O₉, Nature Communications, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=922750 (Accessed October 16, 2025)