In insulating solids, heat transfer occurs mainly through vibrations in the crystal lattice carried by quasiparticles called phonons. Lacking electric charge and spin, phonons are not expected to interact with magnetic fields. Over the past two decades, however, researchers have observed the thermal Hall effect in many materials: phonons are deflected in a magnetic field, creating a temperature difference. The fundamental mechanisms underlying this phenomenon remain poorly understood.

This project will systematically investigate the origin of the thermal Hall effect in simple, non-magnetic silicon oxide crystals. By performing heat transport experiments under extreme conditions of low temperature and high magnetic field, we aim to isolate the key parameters governing this property. This research will contribute to developing a comprehensive theoretical framework for understanding phonon-magnetic field interactions.