356 research outputs found
Emergence of a Chern-insulating state from a semi-Dirac dispersion
A Chern insulator (quantum anomalous Hall insulator) phase is demonstrated to
exist in a typical semi-Dirac system, the TiO2/VO2 heterostructure. By
combining first-principles calculations with Wannier-based tight-binding model,
we calculate the Berry curvature distribution, finding a Chern number of -2 for
the valence bands, and demonstrate the existence of gapless chiral edge states,
ensuring quantization of the Hall conductivity to 2e^2/h. A new semi-Dirac
model, where each semi-Dirac cone is formed by merging three conventional Dirac
points, is proposed to reveal how the nontrivial topology with finite Chern
number is compatible with a semi-Dirac electronic spectrum.Comment: 12 pages, 3 figure
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