Orbital Kondo effect in CrO2: a combined local-spin-density-approximation dynamical-mean-field-theory study

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Experimental evidence suggests CrO2 exhibits strongly correlated electronic behavior.
• Previous theoretical models like LSDA(+U) and simplified many-body approaches have limitations in fully describing CrO2's properties.

Purpose of the Study:

• To develop and apply a more accurate theoretical framework for investigating the ferromagnetic metallic state of CrO2.
• To achieve better agreement with experimental observations for correlated electron systems.

Main Methods:

• Combined actual band structure calculations with multiorbital dynamical-mean-field theory (DMFT).
• Investigated the electronic, magnetic, and thermodynamic properties of CrO2.

Main Results:

• The combined band structure and DMFT approach yields semiquantitative agreement with photoemission spectroscopy data.
• This method accurately describes the applicability of the half-metal concept in CrO2.
• Thermodynamic and dc transport data are also well-reproduced by this unified theoretical picture.

Conclusions:

• The developed theoretical approach provides a superior description of CrO2 compared to LSDA(+U) and model many-body methods.
• This first-principles method is broadly applicable to the study of other transition metal oxide-based half-metallic ferromagnets.