Study of the influence of weak magnetic fields on phase transitions of the four-component antiferromagnetic Potts model

Using the computer simulation method, phase transitions and thermodynamic properties of the two-dimensional antiferromagnetic Potts model with the number of spin states $q$ = 4 on a hexagonal lattice in weak magnetic fields have been studied. The studies were carried out for the magnetic field range 0.0 $\le h\le$ 5.0 with a step of 0.5. It has been established that in the field range 0.0 $\le h\le$ 3.0 a first-order phase transition is observed. It was found that in the interval 3.5 $\le h\le$ 5.0 the system becomes frustrated.