Anomalous transport of small polarons arises from transient lattice relaxation or immovable boundaries

Fuente: arXiv
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Main Authors: Bhattacharyya, Srijan, Sayer, Thomas, Montoya-Castillo, Andrés
Format: Preprint
Published: 2023
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author Bhattacharyya, Srijan
Sayer, Thomas
Montoya-Castillo, Andrés
author_facet Bhattacharyya, Srijan
Sayer, Thomas
Montoya-Castillo, Andrés
contents Elucidating transport mechanisms and predicting transport coefficients is crucial for advancing material innovation, design, and application. Yet, state-of-the-art calculations are restricted to exact simulations of small lattices with severe finite-size effects or approximate simulations that assume the nature of transport. We leverage recent algorithmic advances to perform exact simulations of the celebrated Holstein model that systematically quantify and eliminate finite-size effects to gain insights into small polaron formation and the nature and timescales of its transport. We perform the first systematic comparison of the performance of two distinct approaches to predict charge carrier mobility: equilibrium-based Green-Kubo relations and nonequilibrium relaxation methods. Our investigation uncovers when and why disparities arise between these ubiquitously used techniques, revealing that the equilibrium-based method is highly sensitive to system topology whereas the nonequilibrium approach requires bigger system sizes to reveal its diffusive region. Contrary to assumptions made in standard perturbative calculations, our results demonstrate that small polarons exhibit anomalous transport and that it manifests transiently, due to nonequilibrium lattice relaxation, or permanently, as a signature of immovable boundaries. These findings have consequences for applications including the utilization of organic polymers in organic electronics and transition metal oxides in photocatalysis.
format Preprint
id arxiv_https___arxiv_org_abs_2309_09509
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Anomalous transport of small polarons arises from transient lattice relaxation or immovable boundaries
Bhattacharyya, Srijan
Sayer, Thomas
Montoya-Castillo, Andrés
Chemical Physics
Materials Science
Elucidating transport mechanisms and predicting transport coefficients is crucial for advancing material innovation, design, and application. Yet, state-of-the-art calculations are restricted to exact simulations of small lattices with severe finite-size effects or approximate simulations that assume the nature of transport. We leverage recent algorithmic advances to perform exact simulations of the celebrated Holstein model that systematically quantify and eliminate finite-size effects to gain insights into small polaron formation and the nature and timescales of its transport. We perform the first systematic comparison of the performance of two distinct approaches to predict charge carrier mobility: equilibrium-based Green-Kubo relations and nonequilibrium relaxation methods. Our investigation uncovers when and why disparities arise between these ubiquitously used techniques, revealing that the equilibrium-based method is highly sensitive to system topology whereas the nonequilibrium approach requires bigger system sizes to reveal its diffusive region. Contrary to assumptions made in standard perturbative calculations, our results demonstrate that small polarons exhibit anomalous transport and that it manifests transiently, due to nonequilibrium lattice relaxation, or permanently, as a signature of immovable boundaries. These findings have consequences for applications including the utilization of organic polymers in organic electronics and transition metal oxides in photocatalysis.
title Anomalous transport of small polarons arises from transient lattice relaxation or immovable boundaries
topic Chemical Physics
Materials Science
url https://arxiv.org/abs/2309.09509