Eliminating Orbital Selectivity from the Metal-Insulator Transition by Strong Magnetic Fluctuations

Area of Science:

• Condensed Matter Physics
• Strongly Correlated Electron Systems
• Materials Science

Background:

• Orbital-selective electronic behavior is a key feature of multiorbital systems with strong electronic correlations.
• The orbital-selective Mott transition (OSMT) describes systems with both localized and itinerant electrons across different orbitals.
• Current theoretical models for OSMT rely on local approximations, neglecting spatial electronic fluctuations.

Purpose of the Study:

• To investigate the impact of spatial collective electronic fluctuations on the orbital-selective Mott transition (OSMT).
• To move beyond local approximations in describing electronic correlations in multiorbital systems.
• To understand the interplay between magnetic fluctuations and orbital selectivity.

Main Methods:

• Utilized a half-filled Hubbard-Kanamori model on a cubic lattice with two orbitals of differing bandwidths.
• Focused on analyzing the role of spatial collective electronic fluctuations beyond local theories.
• Investigated the system's behavior under strong magnetic fluctuations inherent to the model.

Main Results:

• Demonstrated that strong inherent magnetic fluctuations suppress the orbital-selective Mott transition (OSMT).
• Showed that these magnetic fluctuations favor a Néel transition instead of an OSMT.
• The Néel transition occurs at a single critical temperature affecting both orbitals simultaneously.

Conclusions:

• Spatial magnetic fluctuations are crucial and can prevent orbital-selective Mott transitions in certain correlated systems.
• The Néel transition emerges as a dominant instability, overriding orbital selectivity.
• This finding necessitates revising theoretical approaches to strongly correlated multiorbital systems.