Spin, orbital, and charge order at the interface between correlated oxides

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid State Physics

Background:

• The LaVO(3)/SrTiO(3) heterostructure is a key system for studying correlated electron phenomena.
• Understanding the electronic properties at oxide interfaces is crucial for novel device applications.

Purpose of the Study:

• To investigate the collective behavior of correlated electrons in the VO2 interface layer.
• To explain the insulating behavior observed in p-type LaVO(3)/SrTiO(3) interfaces.

Main Methods:

• Utilized a quarter-filled t(2g)-orbital Hubbard model on a square lattice.
• Analyzed the ground state properties, including magnetic ordering and orbital/charge ordering.

Main Results:

• The ground state was found to be ferromagnetic, driven by the double-exchange mechanism.
• Orbital and charge ordering were identified, leading to density waves.
• These density waves open gaps across the entire Fermi surfaces for all orbitals.

Conclusions:

• The theoretical model successfully explains the insulating behavior of the p-type LaVO(3)/SrTiO(3) interface.
• Electron correlations and confined geometry play a critical role in driving the observed electronic properties.