Mott Metal-Insulator Transition from Steady-State Density Functional Theory

Area of Science:

• Condensed Matter Physics
• Computational Materials Science
• Quantum Chemistry

Background:

• Accurate calculation of spectral functions is crucial for understanding material properties.
• Existing methods can be computationally intensive, limiting their application to large or complex systems.
• Steady-state density functional theory (i-DFT) offers a promising framework for electronic structure calculations.

Purpose of the Study:

• To present a computationally efficient method for determining the spectral function of bulk systems.
• To utilize an idealized scanning tunneling microscope (STM) setup within the i-DFT framework.
• To extract spectral information from measurable quantities like differential conductance.

Main Methods:

• Calculation of electric current through a scanning tunneling microscope (STM) tip.
• Extraction of the spectral function from finite-bias differential conductance measurements.
• Implementation of exchange-correlation (XC) contributions within i-DFT, guided by Fermi-liquid theory.
• Development of approximations for the Hubbard model based on XC bias properties.

Main Results:

• The proposed i-DFT method provides a computationally efficient route to spectral functions.
• The exchange-correlation bias in the fictitious noninteracting system correctly reproduces the current of the true interacting system.
• The Mott metal-insulator transition was successfully captured for two distinct lattice structures.
• The method demonstrates the capability of i-DFT in describing fundamental electronic transitions.

Conclusions:

• The developed i-DFT method offers an efficient and accurate approach for spectral function calculations.
• This work validates the use of i-DFT and STM-like setups for studying electronic properties of bulk materials.
• The accurate prediction of the Mott transition highlights the potential of this method for materials discovery and understanding.