Giant and tunable thermal chiral anomaly in the Weyl phase of semiconducting TI Bi_1-xSb_x alloys

Observation of heat transport in quantum material is important tool to understand rich physics.  The thermal chiral anomaly is a new concept for a thermal transport mechanism that occurs in Weyl semimetals. Recently [1], a giant thermal conductivity enhancement is observed in the magnetic-field induced Weyl phase of semiconducting Bi_1-xSb_x alloys, which are topological insulators at zero field. Here, we systematically study thermal chiral anomaly of Bi_1-xSb_x with wide range of x from x=0 to x=0.2 under magnetic field up to 7 Tesla. Our result shows that intensity of thermal chiral anomaly strongly depends on concentration of Sb and high concentration of Sb gives higher thermal conductivity enhancement. This phenomenon is important for not only fundamental interest, but also technological applications because it can be used to dynamic tuning of thermal conductivity (e.g. thermal switch and thermal transistor) without moving part.