Speaker
Description
The Potts model with invisible states was introduced to explain discrepancies between theoretical predictions and experimental observations of phase transitions in some systems where Zq symmetry is spontaneously broken [1]. It differs from the ordinary q-state Potts model in that each spin, besides the usual q visible states, can be also in any of r so-called invisible states. Spins in an invisible state do not interact with their neighbours but they do contribute to the entropy of the system. As a consequence, an increase in r may cause a phase transition to change from second to first order. Potts models with invisible states describe a number of systems of interest in physics and beyond and have been treated by various tools of statistical and mathematical physics. We aim to give a review of this fundamental topic based on our results [2-4]. Mainly, our goal was to investigate the energy-entropy interplay influence on the phase transition in the Potts model with invisible states in 1D case [2] as well as on different graph topologies [3].
We acknowledge support from the National Research Foundation of Ukraine, Project 2023.03/0099 "Criticality of complex systems: fundamental aspects and applications".
[1] S. Tanaka, R. Tamura, N. Kawashima. J. Phys. Conf. Ser., 297 (2011) 012022.
[2]. Petro Sarkanych, Yurij Holovatch, Ralph Kenna. Journ. Phys. A vol. 51 (2018) 505001; Phys. Lett. A vol. 381, (2017) 3589-3593
[3] M. Krasnytska, P. Sarkanych, B. Berche, Yu. Holovatch, R. Kenna. J. Phys. A: Math. Theor., 49(25) (2016) 255001;
P. Sarkanych, M. Krasnytska. Cond. Matt. Phys., 26 (1) (2023) 13507.
[4] M. Krasnytska, P. Sarkanych, B. Berche, Yu. Holovatch, R. Kenna. Eur. Phys. J. Spec. Top. 232, 1681–1691 (2023).
