Thermal transport study of phase transitions and spontaneous orders in zero-energy Landau level

With valley, layers and spin degrees of freedom, the Zero-energy Landau level of bilayer graphene provide a rich phase space where the symmetry broken states can be tuned by applied electric and magnetic fields. In this work, we utilize non-local noise thermometry in a multi-terminal geometry to study thermal transport of the competing orders in this system. With the quantized thermal conductance of quantum Hall edge states as a reference, we extract quantitative behaviors of canted-antiferromagnetism (CAF) and layer-polarized (LP) states. Data from monolayer graphene at charge neutrality will also be discussed for cross-comparison. Our results offer a unique perspective on understanding charge-neutral excitations, such as magnons, in the quantum Hall ferromagnet (QHFM).