Functional renormalization group analysis of the half-filled one-dimensional extended Hubbard model

Area of Science:

• Condensed Matter Physics
• Quantum Many-Body Systems
• Theoretical Physics

Background:

• The extended Hubbard model describes interacting electrons in one dimension.
• Understanding its phase diagram is crucial for condensed matter physics.
• Previous studies using g-ology faced limitations in capturing certain electronic phases.

Purpose of the Study:

• To investigate the phase diagram of the half-filled 1D extended Hubbard model at weak coupling.
• To systematically include scattering processes away from Fermi points.
• To clarify the existence and origin of the bond order wave phase.

Main Methods:

• Utilizing a novel functional renormalization group (FRG) approach.
• Systematically incorporating effects of electron scattering processes.
• Analyzing the model at weak coupling and half-filling.

Main Results:

• Confirmed the existence of a bond charge density wave (bond order wave) phase.
• Identified this phase near the U=2V interaction regime.
• Explained the limitations of prior g-ology calculations in detecting this phase.

Conclusions:

• Formally irrelevant corrections can alter the phase diagram's topology.
• The generalized FRG method is vital for accurate phase diagram characterization.
• This approach is crucial when marginal terms lead to accidental symmetries.