Classical antiferromagnetism in kinetically frustrated electronic models

Area of Science:

• Condensed Matter Physics
• Quantum Many-Body Systems

Background:

• The infinite U Hubbard model is a fundamental model in condensed matter physics.
• Frustrated hoppings in triangular and square lattices can invalidate established theorems like Nagaoka's.
• Understanding the behavior of doped holes in such systems is crucial for predicting magnetic properties.

Purpose of the Study:

• To investigate the ground states of the infinite U Hubbard model with one hole doped away from half filling in frustrated lattices.
• To identify the mechanism behind kinetic antiferromagnetism in these systems.
• To explore how hole motion influences the magnetic background.

Main Methods:

• Density Matrix Renormalization Group (DMRG) was employed for numerical simulations.
• Analysis focused on the thermodynamic limit to capture bulk properties.
• The study examined frustrated hoppings in triangular and square lattice geometries.

Main Results:

• The kinetically frustrated models exhibit antiferromagnetic ground states.
• Classical local magnetization was observed in the thermodynamic limit.
• The mechanism of kinetic antiferromagnetism was identified as the release of kinetic energy frustration.

Conclusions:

• Hole doping in frustrated Hubbard models leads to antiferromagnetic ordering.
• The release of kinetic frustration occurs via spin Berry phase or vanishing hopping amplitudes.
• These findings offer insights into the complex magnetic behaviors of frustrated quantum systems.