Kasahara et al. have reported the observation of a quantized thermal Hall conductivity κ_xy in the Kitaev spin-liquid candidate α-RuCl₃ at low temperature, when antiferromagnetic order is suppressed with an in-plane magnetic field [1]. The reported magnitude of κ_xy / T is consistent with the quantized value expected from topologically protected chiral edge currents of charge-neutral Majorana fermions [2]. If confirmed, this is a major advance in the physics of quantum spin liquids.
Given that the magnitude of both κ_xy and the longitudinal thermal conductivity κ_xx varies greatly from sample to sample [3,4], we report further measurements of heat transport in α-RuCl₃, with the aim of shedding light on the factors responsible for this considerable variability.

[1] Kasahara et al., Nature 559, 227 (2018).
[2] Nasu et al., PRL 119, 127204 (2017).
[3] Kasahara et al., PRL 120, 217205 (2018).
[4] Hentrich et al., arXiv:1803.08162 (2018).