【时间】2026年5月26日（星期二）14:00

【地点】量子院526报告厅

【主持】Katsumi Tanigaki教授  拓扑和二维材料团队

【题目】Thermodynamic crossovers in supercritical states

【摘要】

Can liquid-like and gas-like states be distinguished beyond the critical point, where the liquid-gas phase transition no longer exists and conventionally only a single supercritical fluid phase is defined? Recent experiments and simulations report strong evidence of dynamical crossovers above the critical temperature and pressure. Despite using different criteria, many existing theoretical explanations consider a single crossover line separating liquid-like and gas-like states in the supercritical fluid phase. We argue that such a single-line scenario is inconsistent with the supercritical behavior of the Ising model, which has two crossover lines due to its symmetry, violating the universality principle of critical phenomena. To reconcile the inconsistency, we define two thermodynamic crossover lines in supercritical fluids as boundaries of liquid-like, indistinguishable and gas-like states. Near the critical point, the two crossover lines follow critical scalings with exponents of the Ising universality class, supported by calculations of theoretical models and analyses of experimental data from the standard database. This work provides a fundamental framework for understanding supercritical crossovers in general phase transitions, including magnetic transitions, liquid-gas phase transitions, liquid-liquid phase transitions, quantum phase transition, and thermodynamics of black holes.

References:

[1] X. Li and Y. Jin, Thermodynamic crossovers in supercritical fluids, PNAS 121(18), e2400313121 (2024).

[2] J. Wang, E. Lv, X. Li, Y. Jin, W. Li, Quantum supercritical crossover with dynamical singularity, Physical Review B 112 (19), 195120 (2025).

[3] X. Li, Y. Jin, Supercritical-subcritical correspondence, asymmetric effects and antisymmetric corrections near a critical point, arXiv:2512.08553.

[4] S. Jin, X. Li, X. Fan, M. Baggioli, Y. Jin, Supercritical fluids as a distinct state of matter characterized by sub-short-range structural order, arXiv:2508.07385.

[5] S. Wang, X. Li, Y. Jin, L. Li, Analogous supercritical crossovers in black holes and water, arXiv:2506.10808.

【报告人简介】

Yuliang Jin received his Ph.D. from the City University of New York in 2012. From 2012 to 2018, he held postdoctoral positions at Duke University, Sapienza University of Rome, the école Normale Supérieure in Paris, and Osaka University. In 2018, he joined the Institute of Theoretical Physics at the Chinese Academy of Sciences, becoming a full professor in 2022. His research focuses on soft matter physics, statistical physics, and complex disordered systems, with primary interests in supercritical physics, glass and jamming transitions, and the physics of amorphous solids. He proposed a new definition for supercritical crossover lines, known as the L+ and L– lines, which exhibit universal scaling across various phase transitions. He has published over 50 papers in scientific journals, with work appearing in top-tier publications such as Nature Physics, Physics Reports, PNAS, Science Advances, Nature Communications, and Physical Review Letters.