Geometry dependence of the thermal Hall effect in chiral spin liquids

Gábor B. Halász

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arXiv · 2505.03879

Geometry dependence of the thermal Hall effect in chiral spin liquids

Gábor B. Halász

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Abstract

Recent thermal-transport experiments on the Kitaev magnet $\alpha$-RuCl$_3$ highlight the challenge in identifying chiral quantum spin liquids through their quantized thermal Hall effect. Here, we propose that variations in the underlying sample geometry -- for example, the introduction of appropriate constrictions -- reveal unique aspects of the thermal Hall effect and can be used to determine its origin. By studying standard phenomenological heat-transport equations based on minimal assumptions, we show that, whereas a conventional thermal Hall effect due to, e.g., phonons or magnons is completely geometry independent, a thermal Hall effect originating from a chiral fermion edge mode is significantly enhanced by constrictions at low temperatures. This unique geometry-dependent signature provides a practical approach for identifying chiral spin liquids in candidate materials like $\alpha$-RuCl$_3$ using currently available thermal-transport experiments.

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Gábor B. Halász. 2025-05-06. Geometry dependence of the thermal Hall effect in chiral spin liquids. https://arxiv.org/abs/2505.03879

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