On the in-plane anisotropy of planar thermal Hall effect and thermal conductivity osccilation in RuCl3

Growing experiment evidence support the existence of Kitaev spin liquid phase in RuCl3 with an in-plane magnetic field. Thermal transport measurements have shown oscillation of thermal conductivity (kxx) and planar thermal Hall conductivity (kxy) in RuCl3, both were claimed to be associated with the underlying Kitaev spin liquid phase. However, these remarkable results are marred by extrinsic factors (stacking fault, etc). Here, we aim to provide further insights to the Kitaev physics of RuCl3 by studying the anisotropy behavior of thermal conductivity (ka, kb) and thermal Hall conductivity (kab, kba), in the presence of parallel and orthogonal applied magnetic field (Ba, Bb), on the same sample. I will present our initial results, with four different configurations on two samples (from the same batch). The oscillation of ka and kb were observed in all configurations, showing different peaks and valley with fields applied parallel/perpendicular to the Ru-Ru bond. The thermal Hall signal kab(j//a) and kba (j//b) is only present when field is applied along a-axis. Their behavior is slightly anisotropic, reaching half-quantization value only in the intermediate temperature range. Theoretical interpretation of our results are still on-going.