Scanning-probe and information-concealing machine learning intermediate hexatic phase and critical scaling of solid-hexatic phase transition in deformable particles

¹ Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, SPTE, South China Normal University - Guangzhou 510006, China and Guangdong-Hong Kong Joint Laboratory of Quantum Matter, South China Normal University Guangzhou 510006, China

^(a) weichen.guo@m.scnu.edu.cn (corresponding author)
^(b) aibq@scnu.edu.cn
^(c) liang.he@scnu.edu.cn

Received: 18 October 2021
Accepted: 10 January 2022

Abstract

We investigate the two-dimensional melting of deformable polymeric particles with multi-body interactions described by the Voronoi model. We report machine learning evidence for the existence of the intermediate hexatic phase in this system, and extract the critical exponent for the divergence of the correlation length of the associated solid-hexatic phase transition. Moreover, we clarify the discontinuous nature of the hexatic-liquid phase transition in this system. These findings are achieved by directly analyzing system's spatial configurations with two generic machine learning approaches developed in this work, dubbed “scanning-probe” via which the possible existence of intermediate phases can be efficiently detected, and “information-concealing” via which the critical scaling of the correlation length in the vicinity of generic continuous phase transition can be extracted. Our work provides new physical insights into the fundamental nature of the two-dimensional melting of deformable particles, and establishes a new type of generic toolbox to investigate fundamental properties of phase transitions in various complex systems.