Abstract

Since its first experimental observation in 2005, thermal Hall effect measurement has emerged as a powerful tool to probe charge-neutral excitations in insulators, particularly in magnetic systems. The discovery of the thermal Hall effect in SrTiO3 attracted great attention as the material was non-magnetic but displayed giant thermal Hall conductivity even compared to magnetic systems . In this seminar, I will talk about the recent thermal Hall research and experimental challenges, and the isotope effect on the thermal Hall conductivity of SrTiO3. We discovered [1] a giant suppression of thermal Hall effect upon isotopic substitution of oxygen, which gives a clue towards the possible link between quantum criticality and thermal Hall physics.

[1] S. Sim, H. Yang, H. Kim, M.J. Coak, M. Itoh, Y. Noda and J-G Park, Sizable suppression of thermal Hall effect upon isotopic substitution in SrTiO₃ Phys. Rev. Lett. 126-015901 (2021)