Snake net with a neural network for detecting multiple phases in the phase diagram

Physical review. E, vol. 107, pp. 065303

Abstract

Unsupervised machine learning applied to the study of phase transitions is an ongoing and interesting research direction. The active contour model, also called the snake model, was initially proposed for target contour extraction in two-dimensional images. In order to obtain a physical phase diagram, the snake model with an artificial neural network is applied in an unsupervised learning way by the authors of [Phys. Rev. Lett. 120, 176401 (2018)0031-900710.1103/PhysRevLett.120.176401]. It guesses the phase boundary as an initial snake and then drives the snake to convergence with forces estimated by the artificial neural network. In this work we extend this unsupervised learning method with one contour to a snake net with multiple contours for the purpose of obtaining several phase boundaries in a phase diagram. For the classical Blume-Capel model, the phase diagram containing three and four phases is obtained. Moreover, a balloon force is introduced, which helps the snake to leave a wrong initial position and thus may allow for greater freedom in the initialization of the snake. Our method is helpful in determining the phase diagram with multiple phases using just snapshots of configurations from cold atoms or other experiments without knowledge of the phases.

Authors 4

1. Xiaodong Sun

   Taiyuan University of Technology

   Affiliation as printed

   College of Physics and Optoelectronics, Taiyuan University of Technology, Shanxi 030024, China

2. Huijiong Yang

   Taiyuan University of Technology

   Affiliation as printed

   College of Data Science, Taiyuan University of Technology, Shanxi 030024, China

3. Jie Zhang

   Taiyuan University of Technology

   Affiliation as printed

   College of Physics and Optoelectronics, Taiyuan University of Technology, Shanxi 030024, China

4. Wanzhou Zhang corresponding

   University of Science and Technology of China · Chinese Academy of Sciences · Institute of Theoretical Physics · Taiyuan University of Technology

   Affiliation as printed

   CAS Key Laboratory for Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China

   College of Physics and Optoelectronics, Taiyuan University of Technology, Shanxi 030024, China

   Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China