Buckled honeycomb lattice and unconventional magnetic response

摘要: We study the magnetic response of buckled honeycomb-lattice materials. The buckling breaks sublattice symmetry, enhances spin-orbit coupling, and allows tuning a topological quantum phase transition. As result, there are two doubly degenerate spin-valley coupled massive Dirac bands, which exhibit an unconventional Hall plateau sequence under strong fields. show how to externally control splitting anomalous zeroth Landau levels, prominent level crossing effects, polarizations spin, valley, degrees freedom. In particular, we reveal that in p-n junction, spin-resolved fractionally quantized conductance appears two-terminal measurement with spin-polarized current propagating along interface. low-field regime where quantization is not applicable, provide semiclassical description for transport. comment briefly on effects electron-electron interactions Zeeman couplings electron spins atomic orbitals.