An efficient saddle search method for ordered phase transitions involving translational invariance

Fuente: arXiv
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Autores principales: Cui, Gang, Jiang, Kai, Zhou, Tiejun
Formato: Preprint
Publicado: 2023
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author Cui, Gang
Jiang, Kai
Zhou, Tiejun
author_facet Cui, Gang
Jiang, Kai
Zhou, Tiejun
contents In this work, we propose an efficient nullspace-preserving saddle search (NPSS) method for a class of phase transitions involving translational invariance, where the critical states are often degenerate. The NPSS method includes two stages, escaping from the basin and searching for the index-1 generalized saddle point. The NPSS method climbs upward from the generalized local minimum in segments to overcome the challenges of degeneracy. In each segment, an effective ascent direction is ensured by keeping this direction orthogonal to the nullspace of the initial state in this segment. This method can escape the basin quickly and converge to the transition states. We apply the NPSS method to the phase transitions between crystals, and between crystal and quasicrystal, based on the Landau-Brazovskii and Lifshitz-Petrich free energy functionals. Numerical results show a good performance of the NPSS method.
format Preprint
id arxiv_https___arxiv_org_abs_2310_07108
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle An efficient saddle search method for ordered phase transitions involving translational invariance
Cui, Gang
Jiang, Kai
Zhou, Tiejun
Numerical Analysis
37M05, 49K35, 37N30
In this work, we propose an efficient nullspace-preserving saddle search (NPSS) method for a class of phase transitions involving translational invariance, where the critical states are often degenerate. The NPSS method includes two stages, escaping from the basin and searching for the index-1 generalized saddle point. The NPSS method climbs upward from the generalized local minimum in segments to overcome the challenges of degeneracy. In each segment, an effective ascent direction is ensured by keeping this direction orthogonal to the nullspace of the initial state in this segment. This method can escape the basin quickly and converge to the transition states. We apply the NPSS method to the phase transitions between crystals, and between crystal and quasicrystal, based on the Landau-Brazovskii and Lifshitz-Petrich free energy functionals. Numerical results show a good performance of the NPSS method.
title An efficient saddle search method for ordered phase transitions involving translational invariance
topic Numerical Analysis
37M05, 49K35, 37N30
url https://arxiv.org/abs/2310.07108