SKM 2023 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 49: Critical Phenomena and Phase Transitions

DY 49.10: Vortrag

Donnerstag, 30. März 2023, 17:30–17:45, ZEU 160

Critical phenomena in the two-dimensional dilute Baxter-Wu model — •Alexandros Vasilopoulos¹, Nikolaos G. Fytas¹, Michail Akritidis¹, and Martin Weigel² — ¹Centre for Fluid and Complex Systems, Coventry University, Coventry CV1 5FB, United Kingdom — ²Institut für Physik, TU Chemnitz, 09107 Chemnitz, Germany

We study the question of universality in the two-dimensional spin-1 Baxter-Wu model in the presence of a crystal field Δ. We employ extensive numerical simulations consisting of various types, providing us with complementary results: Wang-Landau sampling at fixed values of Δ and a parallelized variant of the multicanonical approach performed at constant temperature T. A detailed finite-size scaling analysis in the regime of second-order phase transitions in the (Δ, T) phase diagram indicates that the transition belongs to the universality class of the four-state Potts model. Previous controversies with respect to the nature of the transition are discussed and attributed to the presence of strong finite-size effects, especially as one approaches the pentacritical point of the model. Lastly, to facilitate the study of Δ>0, where the two previous methods become increasingly inhibitory, a hybrid algorithm consisting of both a cluster and a single-spin-flip update was implemented and tested.