Split Dirac cones in HgTe/CdTe quantum wells due to symmetry-enforced   level anticrossing at interfaces
  We describe the fine structure of Dirac states in HgTe/CdHgTe quantum wells of critical and close-to-critical thickness and demonstrate the formation of an anticrossing gap between the tips of the Dirac cones driven by interface inversion asymmetry. By combining symmetry analysis, atomistic calculations, and k-p theory with interface terms, we obtain a quantitative description of the energy spectrum and extract the interface mixing coefficient. The zero-magnetic-field splitting of Dirac cones can be experimentally revealed in studying magnetotransport phenomena, cyclotron resonance, Raman scattering, or THz radiation absorption. 
S.A. Tarasenko, M.V. Durnev, M.O. Nestoklon, E.L. Ivchenko, Jun-Wei   Luo, Alex Zunger
cond-mat.mes-hall cond-mat.mtrl-sci