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Main Authors: Dunton, Owen R., Arbaugh, Tom, Starr, Francis W.
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2411.08194
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author Dunton, Owen R.
Arbaugh, Tom
Starr, Francis W.
author_facet Dunton, Owen R.
Arbaugh, Tom
Starr, Francis W.
contents Phase change materials such as Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) are ideal candidates for next-generation, non-volatile, solid-state memory due to the ability to retain binary data in the amorphous and crystal phases, and rapidly transition between these phases to write/erase information. Thus, there is wide interest in using molecular modeling to study GST. Recently, a Gaussian Approximation Potential (GAP) was trained for GST to reproduce Density Functional Theory (DFT) energies and forces at a fraction of the computational cost [Zhou et al. Nature Electronics $\mathbf{6}$, 746-754 (2023)]; however, simulations of large length and time scales are still challenging using this GAP model. Here we present a machine-learned (ML) potential for GST implemented using the Atomic Cluster Expansion (ACE) framework. This ACE potential shows comparable accuracy to the GAP potential but performs orders of magnitude faster. We train the ACE potentials both directly from DFT, as well as using a recently introduced indirect learning approach where the potential is trained instead from an intermediate ML potential, in this case, GAP. Indirect learning allows us to consider a significantly larger training set than could be generated using DFT alone. We compare the directly and indirectly learned potentials and find that both reproduce the structure and thermodynamics predicted by the GAP, and also match experimental measures of GST structure. The speed of the ACE model, particularly when using GPU acceleration, allows us to examine repeated transitions between crystal and amorphous phases in device-scale systems with only modest computational resources.
format Preprint
id arxiv_https___arxiv_org_abs_2411_08194
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Computationally Efficient Machine-Learned Model for GST Phase Change Materials via Direct and Indirect Learning
Dunton, Owen R.
Arbaugh, Tom
Starr, Francis W.
Materials Science
Phase change materials such as Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) are ideal candidates for next-generation, non-volatile, solid-state memory due to the ability to retain binary data in the amorphous and crystal phases, and rapidly transition between these phases to write/erase information. Thus, there is wide interest in using molecular modeling to study GST. Recently, a Gaussian Approximation Potential (GAP) was trained for GST to reproduce Density Functional Theory (DFT) energies and forces at a fraction of the computational cost [Zhou et al. Nature Electronics $\mathbf{6}$, 746-754 (2023)]; however, simulations of large length and time scales are still challenging using this GAP model. Here we present a machine-learned (ML) potential for GST implemented using the Atomic Cluster Expansion (ACE) framework. This ACE potential shows comparable accuracy to the GAP potential but performs orders of magnitude faster. We train the ACE potentials both directly from DFT, as well as using a recently introduced indirect learning approach where the potential is trained instead from an intermediate ML potential, in this case, GAP. Indirect learning allows us to consider a significantly larger training set than could be generated using DFT alone. We compare the directly and indirectly learned potentials and find that both reproduce the structure and thermodynamics predicted by the GAP, and also match experimental measures of GST structure. The speed of the ACE model, particularly when using GPU acceleration, allows us to examine repeated transitions between crystal and amorphous phases in device-scale systems with only modest computational resources.
title Computationally Efficient Machine-Learned Model for GST Phase Change Materials via Direct and Indirect Learning
topic Materials Science
url https://arxiv.org/abs/2411.08194