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Local and Nonlocal Electronic Correlations at the Metal-Insulator Transition in the Two-Dimensional Hubbard Model
Maria Chatzieleftheriou1, Silke Biermann1,2,3, Evgeny A Stepanov1,2
1CPHT, CNRS, <a href="https://ror.org/05hy3tk52">École polytechnique</a>, Institut Polytechnique de Paris, 91120 Palaiseau, France.
Physical Review Letters
|June 21, 2024
Summary
Researchers explored the intermediate-coupling regime of the single-orbital Hubbard model to understand metal-insulator transitions. They identified distinct Slater and Heisenberg regimes separated by a crossover driven by competing correlations, clarifying insulating state formation.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Understanding metal-insulator transitions is crucial for materials science.
- The single-orbital Hubbard model is a key theoretical framework.
- The intermediate-coupling regime remains poorly understood.
Purpose of the Study:
- To elucidate the physics of the single-orbital Hubbard model in the intermediate-coupling regime.
- To disentangle the roles of antiferromagnetic fluctuations and local electronic correlations in forming insulating states.
- To identify and characterize the Slater and Heisenberg regimes and the crossover region.
Main Methods:
- Utilized nonperturbative many-body techniques.
- Interpolated between weak (Slater) and strong (Mott) coupling regimes.
- Obtained and analyzed momentum-resolved spectral functions.
- Investigated the behavior of local magnetic moments.
Main Results:
- Successfully mapped the momentum-resolved spectral function in the intermediate-coupling regime.
- Identified distinct Slater and Heisenberg regimes in the phase diagram.
- Characterized a crossover region where spatial and local electronic correlations compete.
- Linked the behavior of local magnetic moments to the crossover and insulating state formation.
Conclusions:
- The study clarifies the physics governing metal-insulator transitions at intermediate couplings.
- Antiferromagnetic fluctuations and local correlations play distinct but interacting roles.
- The identified crossover region is critical for understanding the transition to insulating states.
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