Bandstructure meets many-body theory: the LDA+DMFT method.

Area of Science:

• Solid-state theory
• Computational materials science
• Condensed matter physics

Background:

• Accurate ab initio calculation of electronic properties is challenging for strongly correlated electron systems.
• Traditional Density-Functional Theory (DFT), like Local Density Approximation (LDA), is insufficient for materials with strong electronic correlations (d- or f-electrons).
• Strongly correlated materials exhibit significant responses to external parameters, making them vital for technological applications.

Purpose of the Study:

• To introduce and validate the combined LDA+DMFT method for ab initio calculations of strongly correlated materials.
• To demonstrate the capability of LDA+DMFT in describing materials with varying degrees of electronic correlation.
• To present results for LaMnO(3) and discuss its relevance to colossal magnetoresistance in doped manganites.

Main Methods:

• Development and application of a hybrid approach combining DFT (specifically LDA) with Dynamical Mean-Field Theory (DMFT).
• Utilizing LDA+DMFT to perform ab initio calculations for materials with strongly correlated electrons.
• Case study using LaMnO(3) to illustrate the method's performance and predictive power.

Main Results:

• The LDA+DMFT method successfully predicts different electronic states (weakly correlated metal, strongly correlated metal, Mott insulator) based on increasing Coulomb correlations.
• Calculations for LaMnO(3) using LDA+DMFT provide insights into its electronic structure.
• The method is shown to be relevant for understanding phenomena like the colossal magnetoresistance observed in doped manganites.

Conclusions:

• LDA+DMFT offers a robust framework for ab initio electronic structure calculations of materials with strong electronic correlations.
• The method advances the understanding of complex materials and their potential applications.
• The study highlights the advantages and limitations of the LDA+DMFT approach for future research.