Antiferromagnetic triangular Blume-Capel model with hard-core exclusions

Area of Science:

• Condensed Matter Physics
• Statistical Mechanics
• Computational Physics

Background:

• Antiferromagnetic (AFM) triangular lattice models are crucial for understanding magnetic materials.
• The Blume-Capel model describes systems with competing interactions and single-ion anisotropy.
• Investigating phase transitions in these models reveals complex magnetic ordering phenomena.

Purpose of the Study:

• To analyze phase transitions in two modified antiferromagnetic triangular Blume-Capel models.
• To investigate the influence of third-nearest neighbor interactions and hard-core exclusions on magnetic ordering.
• To characterize the nature (first-order, second-order, or Berezinskii-Kosterlitz-Thouless) of observed phase transitions.

Main Methods:

• Monte Carlo simulations were employed to model the magnetic systems.
• Finite-size scaling analysis was used to determine the critical behavior and order of phase transitions.
• The effects of varying normalized single-ion anisotropy (δ) were systematically studied.

Main Results:

• Both the 3NN1 and 3NN12 models exhibit transitions from paramagnetic to ordered AFM phases, potentially via intermediate phases.
• Low-temperature transition properties are similar across models for 0 < δ < 1.5.
• The 3NN12 model shows up to three distinct phase transitions (T(c), T(2), T(1)) depending on δ, including BKT-type behavior.

Conclusions:

• The nature of phase transitions is highly dependent on the specific model and the anisotropy parameter.
• The 3NN12 model displays richer phase transition behavior, including a diluted frustrated BKT-type phase.
• These findings contribute to understanding complex magnetic ordering in frustrated lattice systems.