Magnetotransport in a two-dimensional hybrid band system: Dirac and heavy-hole interplay

We investigate magnetoresistivity and the Hall effect in a 6.3 nm gapless HgTe quantum well - a two-dimensional hybrid band system featuring coexisting linear (Dirac-like) and parabolic hole energy bands at low energies. Using a classical two-subband model that incorporates intervalley scattering, we reveal a striking tenfold enhancement of the Hall resistance, primarily driven by the dominant transport contribution of Dirac holes. A comprehensive magnetotransport analysis enables us to extract key parameters, such as the mobilities of both carrier types, thereby providing insight into their complex interplay. These results establish the HgTe quantum well as a distinctive platform for exploring novel transport phenomena in hybrid band systems and deepen our understanding of mixed-carrier magnetotransport.