DFT-1/2 method applied to 3D topological insulators

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Topological insulators (TIs) are materials with unique electronic properties.
• Accurate prediction of their band structure and topological invariants is crucial.
• Standard DFT calculations often struggle with the band inversion region in TIs.

Purpose of the Study:

• To apply and evaluate the DFT-1/2 method for calculating properties of five 3D topological insulators.
• To compare DFT-1/2 results with standard DFT and experimental findings.
• To assess the efficiency and accuracy of DFT-1/2 for topological materials.

Main Methods:

• Density Functional Theory with a half-integer self-interaction correction (DFT-1/2).
• Application to Bi2Se3, Bi2Te3, Sb2Te3, CuTlSe2, and CuTlS2.
• Calculation of band gaps, band dispersion, and topological invariants (Z2).

Main Results:

• DFT-1/2 provides accurate band gaps and band structures near the inversion region.
• The method correctly predicts the atomic character of bands.
• Topological invariants are reliably calculated, essential for characterizing TIs.
• Results show significant improvements over standard DFT for these materials.

Conclusions:

• DFT-1/2 is an efficient and accurate method for studying 3D topological insulators.
• It offers precise predictions of electronic and topological properties.
• The method is computationally cost-effective, suitable for complex systems.