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arXiv · 2008.09923

Thermal and magnetoelastic properties of α-RuCl3 in the field-induced low temperature states

Rico Schönemann·Shusaku Imajo·Franziska Weickert·Jiaqiang Yan·David G. Mandrus·Yasumasa Takano·Eric L. Brosha·Priscila F. S. Rosa·Stephen E. Nagler·Koichi Kindo·Marcelo Jaime
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Abstract

We discuss the implications that new magnetocaloric, thermal expansion and magnetostriction data in $α$-RuCl$_{3}$ single crystals have on its temperature-field phase diagram and uncover the magnetic-field dependence of an apparent energy gap structure $Δ(H)$ that evolves when the low temperature antiferromagnetic order is suppressed. We show that, depending on how the thermal expansion data is modeled, $Δ(H)$ can show a cubic field dependence and remain finite at zero field, consistent with the pure Kitaev model hosting itinerant Majorana fermions and localized $\mathbb{Z}_{2}$ fluxes. Our magnetocaloric effect data provides, below $1\,\mathrm{K}$, unambiguous evidence for dissipative phenomena at $H_{\mathrm{c}}$, smoking gun for a first order phase transition. Our results, on the other hand, show little support for a phase transition from a QSL to a polarized paramagnetic state above $H_{\mathrm{c}}$.

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Rico Schönemann, Shusaku Imajo, Franziska Weickert, Jiaqiang Yan, David G. Mandrus, Yasumasa Takano, Eric L. Brosha, Priscila F. S. Rosa, Stephen E. Nagler, Koichi Kindo, Marcelo Jaime. 2021-01-11. Thermal and magnetoelastic properties of α-RuCl3 in the field-induced low temperature states. https://doi.org/10.1103/physrevb.102.214432

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