Investigation of the thermal Hall effect in a Kagome antiferromagnet

Quantum spin liquid (QSL) is an exotic quantum state of matter in which spins are highly entangled and disordered at zero temperature. The recently discovered Kagome lattice antiferromagnet YCu3-Br has become a promising QSL candidate. The experimental results, including low-temperature magnetization, heat capacity, inelastic neutron scattering, and magnetic oscillations, are all consistent with the expectation of QSL with Dirac spinon.

On the other hand, the thermal Hall effect has emerged as a probe of QSL. For QSLs with spinon Fermi surfaces, it was theoretically proposed that the external magnetic field generates an internal gauge field and could exert Lorentz force on the neutral spinon, leading to a significant thermal Hall effect. We present a comprehensive study of thermal conductivity as well as the thermal hall effect in the YCu3-Br single crystals. The experimental methods, verification, and possible explanations will be discussed.