Massless Dirac fermions in semimetal HgCdTe

Magneto-transport results obtained for the strained 100 nm thick Hg1−x CdxTe (x=0.135) layer grown by MBE on the CdTe/GaAs substrate are interpreted by the 8×8 kp model with the in-plane tensile strain. The dispersion relation for the investigated structure proves that the Dirac point is located in the gap caused by the strain. It is also shown that the fan of the Landau Levels (LL's) energy calculated for topological protected surface states for the studied HgCdTe alloy corresponds to the fan of the LL's calculated using the graphen-like Hamiltonian which gives excellent agreement with the experimental data for velocity on the Fermi level equal to vf≈ 0.85×106 m/s. That characterized strained Hg1−x CdxTe layers (0.13