报告题目：Higher-order phase transitions in finite systems
报 告 人：Prof. Atahualpa S. Kraemer, 墨西哥国立自治大学物理系
报告时间：2025年12月26日 周五上午10:00-11:00
报告地点：物理科技楼 101室
报告摘要：Phase transitions are conventionally defined by discontinuities in the derivatives of thermodynamic potentials within the thermodynamic limit (V to infinity and N to infinity). Consequently, identifying these transitions in finite systems poses a significant theoretical and numerical challenge. While first- and second-order transitions—characterized by discontinuities in the first and second derivatives—are well-documented computationally, higher-order transitions remain elusive. In this talk, we review the criteria for phase transitions in finite systems and provide numerical evidence of two third-order phase transitions in the Ising model. We demonstrate that one of these transitions acts as a precursor to the classic Onsager phase transition.
报告人简介：Prof. Atahualpa S. Kraemercompleted his B.Sc. and Ph.D. in Physics at the National Autonomous University of Mexico (UNAM) between 2003 and 2013. Following my doctoral studies, he held postdoctoral positions at Heinrich Heine University Düsseldorf and the University of Erlangen-Nuremberg, Germany (2014–2016). In 2016, he joined the Faculty of Sciences at UNAM as an Associate Professor, where he was promoted to Full Professor in 2023. During that year, he was a visiting scholar at the Institute of Physics of the Chinese Academy of Sciences through the Presidential International Fellowship Initiative (PIFI). He was also recognized as a candidate for the National University Award for Young Researchers (Reconocimiento Distinción Universidad Nacional para Jóvenes Académicos). Most recently, in 2024, he served as a Visiting Professor at the University of Erlangen-Nuremberg.
