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arXiv · 1705.01312

Relation between Kitaev magnetism and structure in $α$-RuCl$_3$

A. Glamazda·P. Lemmens·S. -H. Do·Y. S. Kwon·K. -Y. Choi
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Abstract

Raman scattering has been employed to investigate lattice and magnetic excitations of the honeycomb Kitaev material $α$-RuCl$_3$ and its Heisenberg counterpart CrCl$_3$. Our phonon Raman spectra give evidence for a first-order structural transition from a monoclinic to a rhombohedral structure for both compounds. Significantly, only $α$-RuCl$_3$ features a large thermal hysteresis, consistent with the formation of a wide phase of coexistence. In the related temperature interval of $70-170$ K, we observe a hysteretic behavior of magnetic excitations as well. The stronger magnetic response in the rhombohedral compared to the monoclinic phase evidences a coupling between the crystallographic structure and low-energy magnetic response. Our results demonstrate that the Kitaev magnetism concomitant with fractionalized excitations is susceptible to small variations of bonding geometry.

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A. Glamazda, P. Lemmens, S. -H. Do, Y. S. Kwon, K. -Y. Choi. 2017-05-03. Relation between Kitaev magnetism and structure in $α$-RuCl$_3$. https://doi.org/10.1103/physrevb.95.174429

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