Mott transitions in multiorbital systems

Area of Science:

• Condensed matter physics
• Materials science
• Quantum mechanics

Background:

• Nonisotropic multiorbital materials exhibit complex electronic behaviors.
• Mott transitions are crucial phenomena in understanding correlated electron systems.
• Understanding excitation spectra is key to characterizing material phases.

Purpose of the Study:

• To investigate the role of interorbital Coulomb interactions in nonisotropic multiorbital materials.
• To analyze the nature of the Mott transition in these systems.
• To explore the relationship between insulating and superconducting behaviors.

Main Methods:

• Dynamical Mean Field Theory (DMFT) was employed to model the electronic structure.
• Analysis focused on the differences in excitation spectra between metallic and insulating phases.
• Comparison was made between "multigap" insulating behavior and multigap superconductivity.

Main Results:

• A single Mott transition is predicted to arise from interorbital Coulomb interactions.
• Narrow and wide subbands display distinct excitation spectra in both metallic and insulating states.
• A significant analogy between "multigap" insulating states and multigap superconductivity was identified.

Conclusions:

• Interorbital Coulomb interactions drive a unified Mott transition in these materials.
• Subband-dependent excitation spectra provide insights into distinct electronic phases.
• The observed analogy suggests potential links between insulating and superconducting mechanisms in multigap systems.