Machine learning phase transitions of the three-dimensional Ising universality class*

作者：Li, Xiaobing; Guo, Ranran; Zhou, Yu; Liu, Kangning; Zhao, Jia; Long, Fen; Wu, Yuanfang; Li, Zhiming^*

来源：Chinese Physics C, 2023, 47(3): 034101.

DOI：10.1088/1674-1137/aca5f5

• machine learning
• phase transition
• QCD critical point
• three-dimensional Ising universality class

Exploration of the QCD phase diagram and critical point is one of the main goals in current relativistic heavy-ion collisions. The QCD critical point is expected to belong to a three-dimensional (3D) Ising universality class. Machine learning techniques are found to be powerful in distinguishing different phases of matter and provide a new way to study the phase diagram. We investigate phase transitions in the 3D cubic Ising model using supervised learning methods. It is found that a 3D convolutional neural network can be trained to effectively predict physical quantities in different spin configurations. With a uniform neural network architecture, it can encode phases of matter and identify both second- and first-order phase transitions. The important features that discriminate different phases in the classification processes are investigated. These findings can help study and understand QCD phase transitions in relativistic heavy-ion collisions.