Carrier mobilities and electron-phonon interactions beyond DFT.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Electron-phonon coupling is crucial for understanding material properties like conductivity and superconductivity.
• Calculating these interactions using methods beyond standard density-functional theory (DFT) presents significant computational challenges.

Purpose of the Study:

• To develop a novel, robust, and accessible finite-difference framework for computing electron-phonon couplings.
• To enable calculations using advanced electronic structure methods beyond DFT.

Main Methods:

• Introduced a finite-difference framework applicable to any electronic structure method yielding eigenvalues and eigenvectors.
• Developed a novel projectability scheme based on eigenvalue differences, overcoming limitations of direct finite difference methods.
• Leveraged symmetries to reduce computational cost and integrated with existing first-principles codes.

Main Results:

• Successfully applied the framework to hybrid, Koopmans, and G W functionals.
• Demonstrated improved accuracy in estimating carrier drift mobilities and effective masses for silicon and gallium arsenide.
• Showcased that advanced functionals predict distinct electron-phonon couplings and modify band curvatures.

Conclusions:

• The developed framework provides a versatile and efficient tool for calculating electron-phonon properties.
• Enables more accurate predictions of material properties by utilizing state-of-the-art electronic structure methods.
• Facilitates deeper understanding of electron-phonon interactions in diverse materials.