Large Oscillatory Thermal Hall Effect in Kagome Metals

TL;DR

This paper reports a large oscillatory thermal Hall effect in Kagome metals, revealing quantum oscillations that challenge conventional laws and offer new insights into correlated quantum materials.

Contribution

It demonstrates the first observation of pronounced oscillatory thermal Hall signals with phase flips, surpassing electrical Hall oscillations, thus providing a novel probe for quantum states in correlated materials.

Findings

Oscillatory thermal Hall effect with phase flip observed.

QOs in thermal Hall surpass electrical Hall QOs.

Violation of Wiedemann Franz law for QOs.

Abstract

The thermal Hall effect recently provided intriguing probes to the ground state of exotic quantum matters. These observations of transverse thermal Hall signals lead to the debate on the fermionic versus bosonic origins of these phenomena. The recent report of quantum oscillations (QOs) in Kitaev spin liquid points to a possible resolution. The Landau level quantization would most likely capture only the fermionic thermal transport effect. However, the QOs in the thermal Hall effect are generally hard to detect. In this work, we report the observation of a large oscillatory thermal Hall effect of correlated Kagome metals. We detect a 180-degree phase change of the oscillation and demonstrate the phase flip as an essential feature for QOs in the thermal transport properties. More importantly, the QOs in the thermal Hall channel are more profound than those in the electrical Hall channel, which strongly violates the Wiedemann Franz (WF) law for QOs. This result presents the oscillatory thermal Hall effect as a powerful probe to the correlated quantum materials.