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arXiv · 2202.03681

Breakdown of Linear Spin-wave Theory and Existence of Spinon Bound States in the Frustrated Kagome Lattice Antiferromagnet

K. Matan·T. Ono·S. Ohira-Kawamura·K. Nakajima·Y. Nambu·T. J. Sato
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Abstract

Spin dynamics of the spin-1/2 kagome lattice antiferromagnet Cs$_2$Cu$_3$SnF$_{12}$ was studied using high-resolution, time-of-flight inelastic neutron scattering. The flat mode, a characteristic of the frustrated kagome antiferromagnet, and the low-energy dispersive mode, which is dominated by magnons, can be well described by the linear spin-wave theory. However, the theory fails to describe three weakly dispersive modes between 9 and 14 meV. These modes could be attributed to two-spinon bound states, which decay into free spinons away from the zone center and at a high temperature, giving rise to continuum scattering.

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K. Matan, T. Ono, S. Ohira-Kawamura, K. Nakajima, Y. Nambu, T. J. Sato. 2022-02-08. Breakdown of Linear Spin-wave Theory and Existence of Spinon Bound States in the Frustrated Kagome Lattice Antiferromagnet. https://doi.org/10.1103/physrevb.105.134403

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