Prof. Minoru Yamashita (ISSP, University of Tokyo)
"Thermal Hall measurements in kagome antiferromagnet volborthite"
Quantum spin liquids (QSLs) in two-dimension are expected to host novel quasi-particles. However, identifying the quasi particles which characterize 2D QSLs remains a major challenge for both experimentally and theoretically. From thermal-transport measurements of a kagome antiferromagnet, volborthite, we find that the spin thermal transport shows a thermal Hall effect in the QSL state. We find an intimate relation between the temperature dependence of the thermal Hall conductivity and that of the spin correlation. We would like to discuss the origin of the thermal Hall effect and the effect of the spin correlation.