▎ 摘　　要

The quantum thermal Hall effect in a six-terminal graphene device subjected to a thermal gradient and a perpendicular magnetic field is theoretically studied. We find that, when the Dirac-point energy is far away from the Fermi energy, the Hall thermal resistance has well-quantized plateaus and the longitudinal thermal resistance is zero at low temperature. On the other hand, when the Dirac-point energy is near the Fermi energy, a fine structure with a negative Hall-Lorentz number is exhibited in which the Wiedemann-Franz law is violated. This fine structure has a good scaling behavior and the analytical scaling functions are also obtained.